Exhibit 3.1
                                                                     -----------
                      The Commonwealth of Massachusetts
                                                                         FEDERAL
                                                                  IDENTIFICATION
                           MICHAEL JOSEPH CONNOLLY                NO. 04-2866152
                              Secretary of State                      ----------
                   One Ashburton Place, Boston, Mass: 02108
 
 
                      RESTATED ARTICLES OF ORGANIZATION
 
                    General Laws, Chapter 156B, Section 74
 
     This certificate must be submitted to the Secretary of the Commonwealth
within sixty days after the date of the vote of stockholders adopting the
restated articles of organization.  The fee for filing this certificate is
prescribed by General Laws, Chapter 156B, Section 114.  Make check payable to
the Commonwealth of Massachusetts.
 
                                -------------
 
We,  Steve C. Walske, President, and
     Steven N. Farber, Assistant Clerk of
 
                      Parametric Technology Corporation
                      ---------------------------------
                            (Name of Corporation)
 
located at   128 Technology Drive, Waltham, Massachusetts 02154
           ----------------------------------------------------
do hereby certify that the following restatement of the articles of organization
of the corporation was duly adopted at a meeting held on February 4, 1993, by
vote of the Board of Directors (see Rider A)
 
     1. The name by which the corporation shall be known is:
 
           Parametric Technology Corporation
 
 
     2. The purposes for which the corporation is formed are as follows:
 
        (a)  To engage in the business of developing and marketing computer
             software.
 
        (b)  To carry on any business or other activity which may lawfully be
             carried on by a corporation organized under the Business
             Corporation Law of the Commonwealth of Massachusetts, whether or
             not related to those referred to in the preceding paragraph.
<PAGE>
 
Note:  If the space provided under any article or item on this form is
insufficient, additions shall be set forth on  separate 8 1/2 x 11 sheets of
paper leaving a left hand margin of at least 1 inch for binding.  Additions to
more than one article may be continued on a single sheet so long as each article
requiring each such addition is clearly indicated.
<PAGE>
 
3.  The total number of shares and the par value, if any, of each class of stock
    which the corporation is authorized to issue is as follows:
 
<TABLE>
<CAPTION>
 
                    WITHOUT PAR VALUE        WITH PAR VALUE
                    -----------------  ---------------------------
  CLASS OF STOCK    NUMBER OF SHARES   NUMBER OF SHARES  PAR VALUE
- ------------------  -----------------  ----------------  ---------
<S>                 <C>                <C>               <C>
 
       Preferred          None                5,000,000       $.01
 
       Common             None               75,000,000       $.01
 
</TABLE>
 
 
*4. If more than one class is authorized, a description of each of the
    different classes of stock with, if any, the preferences, voting powers,
    qualifications, special or relative rights or privileges as to each class
    thereof and any series now established:
 
                               See Attachment 4
 
 
 
 
*5. The restrictions, if any, imposed by the articles of organization upon the
    transfer of shares of stock of any class are as follows:
 
                                     None
 
 
 
 
*6. Other lawful provisions, if any, for the conduct and regulation of the
    business and affairs of the corporation, for its voluntary dissolution, or
    for limiting, defining, or regulating the powers of the corporation, or of
    its directors or stockholders, or of any class of stockholders:
 
                               See Attachment 6
 
 
 
 
*  If there are no such provisions, state "None".
<PAGE>
 
*  We further certify that the foregoing restated articles of organization
   effect no amendments to the articles of organization of the corporation as
   heretofore amended, except amendments to the following articles    None
                                                                   ----------
 
 
                 Briefly describe amendments in space below:
 
 
 
 
 
 
 
 
IN WITNESS WHEREOF AND UNDER THE PENALTIES OF PERJURY, we have hereto signed our
names this    4th    day of     February   in the year 1993
 
   /s/ Steven C. Walske                                           President
- -----------------------                                                  
Steven C. Walske
 
   /s/ Steven N. Farber                                     Assistant Clerk
- -----------------------                                                    
Steven N. Farber
<PAGE>
 
                      THE COMMONWEALTH OF MASSACHUSETTS
 
 
                      RESTATED ARTICLES OF ORGANIZATION
                   (General Laws, Chapter 156B, Section 74)
 
 
                    I hereby approve the within restated
              articles of organization and, the filing fee in
              the amount of $200.00 having been paid, said
              articles are deemed to have been filed with me
              this 5th day of February, 1993
 
 
 
                                              /s/ Michael Joseph Connolly
 
                                                MICHAEL JOSEPH CONNOLLY
                                                   Secretary of State
 
 
 
                        TO BE FILLED IN BY CORPORATION
 
          PHOTO COPY OF RESTATED ARTICLES OF ORGANIZATION TO BE SENT
 
       TO:
            Lynnette C. Fallon
            Palmer & Dodge
            --------------
 
            One Beacon Street
            -----------------
 
            Boston, MA  02108
            -----------------
 
            Telephone    (617) 573-0220
                       ----------------
 
<PAGE>
 
                                   RIDER A
 
 
     These Restated Articles of Organization do not contain any amendments,
but merely restate the corporation's Restated Articles of Organization as
heretofore amended to reflect the fact that the corporation's previously
authorized shares of Series A Convertible Preferred Stock, Series AA Convertible
Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible
Preferred Stock have been reacquired by the corporation and are therefore not
available for issuance in accordance with the terms of subsections (C)(5),
(D)(6)(d) and (E)(6)(d) of Section III of Article 4 of the existing Restated
Articles of Organization.  Accordingly, these Restated Articles of Organization
eliminate those provisions of the corporation's existing Restated Articles of
Organization which are unnecessary by (i) reducing the authorized Preferred
Stock by 4,768,000, being the number of shares of such reacquired designated
Preferred Stock, and (ii) deleting the terms of such reacquired designated
series of Preferred Stock.
<PAGE>
 
                                 ATTACHMENT 4
                                 ------------
 
 
     The following is a statement of the designation and the powers,
privileges and rights, and the qualifications, limitations or restrictions
thereof in respect of each class of capital stock of the corporation.
 
     COMMON STOCK.
     ------------ 
 
     1.   General.  The voting, dividend and liquidation rights of the holders
          -------                                                             
of the Common Stock are subject to and qualified by the rights of the holders of
the Preferred Stock of any series as may be designated by the Board of Directors
upon any issuance of the Preferred Stock of any series.
 
     2.   Voting.  The holders of the Common Stock are entitled to one vote for
          ------                                                               
each share held at all meetings of stockholders (and written actions in lieu of
meetings).  There shall be no cumulative voting.
 
     3.   Dividends.  Dividends may be declared and paid on the Common Stock
          ---------                                                         
from funds lawfully available therefor as and when determined by the Board of
Directors and subject to any preferential dividend rights of any then
outstanding Preferred Stock.
 
     4.   Liquidation.  Upon the dissolution or liquidation of the corporation,
          -----------                                                          
whether voluntary or involuntary, holders of Common Stock will be entitled to
receive all assets of the corporation available for distribution to its
stockholders, subject to any preferential rights of any then outstanding
Preferred Stock.
 
     UNDESIGNATED PREFERRED STOCK.
     ---------------------------- 
 
     Up to 5,000,000 shares of Preferred Stock may be issued from time to time
in one or more series, each of such series to have such terms as stated or
expressed herein and in the resolution or resolutions providing for the issue of
such series adopted by the Board of Directors of the corporation as hereinafter
provided.  Any such shares of Preferred Stock which may be redeemed, purchased
or acquired by the corporation may be reissued except as otherwise provided by
law.  Different such series of Preferred Stock shall not be construed to
constitute different classes of shares for the purposes of voting by classes
unless expressly provided.
 
     Authority is hereby expressly granted to the Board of Directors from time
to time to issue up to 5,000,000 shares of Preferred Stock in one or more
series, and in connection with the creation of any such series, by resolution or
resolutions providing for the issue of the shares thereof, to determine and fix
such voting powers, full or limited, or no voting powers, and such designations,
preferences and relative participating, optional or other special rights, and
qualifications, limitations or restrictions thereof, including without
limitation thereof, dividend rights, conversion rights, redemption privileges
and liquidation preferences, as shall be stated and
<PAGE>
 
expressed in such resolutions, all to the full extent now or hereafter
permitted by Chapter 156B of the Massachusetts General Laws.  Without limiting
the generality of the foregoing, the resolutions providing for issuance of any
such series of Preferred Stock may provide that such series shall be superior
or rank equally or be junior to the Preferred Stock of any other series to the
extent permitted by law and the terms of these Articles of Organization. 
Except as specifically provided in these Articles of Organization, no vote of
the holders of the Preferred Stock or Common Stock shall be a prerequisite to
the issuance of any shares of any series of the Preferred Stock authorized by
and complying with the conditions of the Articles of Organization, the right to
have such vote being expressly waived by all present and future holders of the
capital stock of the corporation.
<PAGE>
 
                                 ATTACHMENT 6
                                 ------------
 
6.   Other lawful provisions, if any, for the conduct and regulation of the
     business and affairs of the corporation, for its voluntary dissolution, or
     for limiting, defining, or regulating the powers of the corporation, or of
     its directors or stockholders, or of any class of stockholders:
 
 
6A.  LIMITATION OF DIRECTOR LIABILITY
     --------------------------------
 
Except to the extent that Chapter 156B of the Massachusetts General Laws
prohibits the elimination or limitation of liability of directors for breaches
of fiduciary duty, no director of the corporation shall be personally liable to
the corporation or its stockholders for monetary damages for any breach of
fiduciary duty as a director, notwithstanding any provision of law imposing such
liability.  No amendment to or repeal of this provision shall apply to or have
any effect on the liability or alleged liability of any director of the
corporation for or with respect to any acts or omissions of such director
occurring prior to such amendment.
 
 
6B.  INDEMNIFICATION
     ---------------
 
     1.   Actions, Suits and Proceedings.  The corporation shall indemnify each
          ------------------------------                                       
person who was or is a party or is threatened to be made a party to any
threatened, pending or completed action, suit or proceeding, whether civil,
criminal, administrative or investigative, by reason of the fact that he is or
was, or has agreed to become, a director or officer of the corporation, or is or
was serving, or has agreed to serve, at the request of the corporation, as a
director or officer of, or in a similar capacity with, another organization or
in any capacity with respect to any employee benefit plan of the corporation
(all such persons being referred to hereafter as an "Indemnitee"), or by reason
of any action alleged to have been taken or omitted in such capacity, against
all expenses (including attorneys' fees), judgments and fines incurred by him or
on his behalf in connection with such action, suit or proceeding and any appeal
therefrom, unless the Indemnitee shall be finally adjudicated in such action,
suit or proceeding not to have acted in good faith in the reasonable belief that
his action was in the best interests of the corporation or, to the extent such
matter relates to service with respect to an employee benefit plan, in the best
interests of the participants or beneficiaries of such employee benefit plan.
Notwithstanding anything to the contrary in this Article, except as set forth in
Section 5 below, the corporation shall not indemnify an Indemnitee seeking
indemnification in connection with a proceeding (or part thereof) initiated by
the Indemnitee unless the initiation thereof was approved by the Board of
Directors of the corporation.
 
     2.   Settlements.  The right to indemnification conferred in this Article
          -----------                                                         
shall include the right to be paid by the corporation for amounts paid in
settlement of any such action, suit or proceeding and any appeal therefrom, and
all expenses (including attorneys' fees) incurred in connection with such
settlement, pursuant to a consent decree or otherwise, unless and to the
<PAGE>
 
extent it is determined pursuant to Section 5 below that the Indemnitee did not
act in good faith in the reasonable belief that his action was in the best
interests of the corporation or, to the extent such matter relates to service
with respect to an employee benefit plan, in the best interests of the
participants or beneficiaries of such employee benefit plan.
 
     3.   Notification and Defense of Claim.  As a condition precedent to his
          ---------------------------------                                  
right to be indemnified, the Indemnitee must notify the corporation in writing
as soon as practicable of any action, suit, proceeding or investigation
involving him for which indemnity will or could be sought.  With respect to any
action, suit, proceeding or investigation of which the corporation is so
notified, the corporation will be entitled to participate therein at its own
expense and/or to assume the defense thereof at its own expense, with legal
counsel reasonably acceptable to the Indemnitee.  After notice from the
corporation to the Indemnitee of its election so to assume such defense, the
corporation shall not be liable to the Indemnitee for any legal or other
expenses subsequently incurred by the Indemnitee in connection with such claim,
other than as provided below in this Section 3.  The Indemnitee shall have the
right to employ his own counsel in connection with such claim, but the fees and
expenses of such counsel incurred after notice from the corporation of its
assumption of the defense thereof shall be at the expense of the Indemnitee
unless (i) the employment of counsel by the Indemnitee has been authorized by
the corporation, (ii) counsel to the Indemnitee shall have reasonably concluded
that there may be a conflict of interest or position on any significant issue
between the corporation and the Indemnitee in the conduct of the defense of such
action or (iii) the corporation shall not in fact have employed counsel to
assume the defense of such action, in each of which cases the fees and expenses
of counsel for the Indemnitee shall be at the expense of the corporation, except
as otherwise expressly provided by this Article.  The corporation shall not be
entitled to assume the defense of any claim brought by or in the right of the
corporation or as to which counsel for the Indemnitee shall have reasonably made
the conclusion provided for in clause (ii) above.
 
     4.   Advance of Expenses.  Subject to the provisions of Section 5 below, in
          -------------------                                                   
the event that the corporation does not assume the defense pursuant to Section 3
of this Article of any action, suit, proceeding or investigation of which the
corporation receives notice under this Article, any expenses (including
attorneys' fees) incurred by an Indemnitee in defending a civil or criminal
action, suit, proceeding or investigation or any appeal therefrom shall be paid
by the corporation in advance of the final disposition of such matter, provided,
                                                                       -------- 
however, that the payment of such expenses incurred by an Indemnitee in advance
- --------                                                                       
of the final disposition of such matter shall be made only upon receipt of an
undertaking by or on behalf of the Indemnitee to repay all amounts so advanced
in the event that it shall ultimately be determined that the Indemnitee is not
entitled to be indemnified by the corporation as authorized in this Article.
Such undertaking may be accepted without reference to the financial ability of
the Indemnitee to make such repayment.
 
     5.   Procedure for Indemnification.  In order to obtain indemnification or
          -----------------------------                                        
advancement of expenses pursuant to Section 1, 2 or 4 of this Article, the
Indemnitee shall submit to the corporation a written request, including in such
request such documentation and information as is reasonably available to the
Indemnitee and is reasonably necessary to determine whether and to what extent
the Indemnitee is entitled to indemnification or advancement of expenses.  Any
such indemnification or advancement of expenses shall be made promptly, and in
any event within 60
<PAGE>
 
days after receipt by the corporation of the written request of the Indemnitee,
unless the corporation determines, by clear and convincing evidence, within
such 60-day period that the Indemnitee did not meet the applicable standard of
conduct set forth in Section 1 or 2, as the case may be. Such determination
shall be made in each instance by (a) a majority vote of a quorum of directors
of the corporation, (b) a majority vote of a quorum of the outstanding shares
of stock of all classes entitled to vote for directors, voting as a single
class, which quorum shall consist of stockholders who are not at that time
parties to the action, suit or proceeding in question, (c) independent legal
counsel (who may be regular legal counsel to the corporation), or (d) a court
of competent jurisdiction.
 
     6.   Remedies.  The right to indemnification or advances as granted by this
          --------                                                              
Article shall be enforceable by the Indemnitee in any court of competent
jurisdiction if the corporation denies such request, in whole or in part, or if
no disposition thereof is made within the 60-day period referred to above in
Section 5.  Unless otherwise provided by law, the burden of proving that the
Indemnitee is not entitled to indemnification or advancement of expenses under
this Article shall be on the corporation.  Neither the failure of the
corporation to have made a determination prior to the commencement of such
action that indemnification is proper in the circumstances because the
Indemnitee has met the applicable standard of conduct, nor an actual
determination by the corporation pursuant to Section 5 that the Indemnitee has
not met such applicable standard of conduct, shall be a defense to the action or
create a presumption that the Indemnitee has not met the applicable standard of
conduct.  The Indemnitee's expenses (including attorneys' fees) incurred in
connection with successfully establishing his right to indemnification, in whole
or in part, in any such proceeding shall also be indemnified by the corporation.
 
     7.   Subsequent Amendment.  No amendment, termination or repeal of this
          --------------------                                              
Article or of the relevant provisions of Chapter 156B of the Massachusetts
General Laws or any other applicable laws shall affect or diminish in any way
the rights of any Indemnitee to indemnification under the provisions hereof with
respect to any action, suit, proceeding or investigation arising out of or
relating to any actions, transactions or facts occurring prior to the final
adoption of such amendment, termination or repeal.
 
     8.   Other Rights.  The indemnification and advancement of expenses
          ------------                                                  
provided by this Article shall not be deemed exclusive of any other rights to
which an Indemnitee seeking indemnification or advancement of expenses may be
entitled under any law (common or statutory), agreement or vote of stockholders
or directors or otherwise, both as to action in his official capacity and as to
action in any other capacity while holding office for the corporation, and shall
continue as to an Indemnitee who has ceased to be a director or officer, and
shall inure to the benefit of the estate, heirs, executors and administrators of
the Indemnitee.  Nothing contained in this Article shall be deemed to prohibit,
and the corporation is specifically authorized to enter into, agreements with
officers and directors providing indemnification rights and procedures different
from those set forth in this Article.  In addition, the corporation may, to the
extent authorized from time to time by its Board of Directors, grant
indemnification rights to other employees or agents of the corporation or other
persons serving the corporation and such rights may be equivalent to, or greater
or less than, those set forth in this Article.
<PAGE>
 
     9.   Partial Indemnification.  If an Indemnitee is entitled under any
          -----------------------                                         
provision of this Article to indemnification by the corporation for some or a
portion of the expenses (including attorneys' fees), judgments, fines or amounts
paid in settlement actually and reasonably incurred by him or on his behalf in
connection with any action, suit, proceeding or investigation and any appeal
therefrom but not, however, for the total amount thereof, the corporation shall
nevertheless indemnify the Indemnitee for the portion of such expenses
(including attorneys' fees), judgments, fines or amounts paid in settlement to
which the Indemnitee is entitled.
 
     10.  Insurance.  The corporation may purchase and maintain insurance, at
          ---------                                                          
its expense, to protect itself and any director, officer, employee or agent of
the corporation or another organization or employee benefit plan against any
expense, liability or loss incurred by him in any such capacity, or arising out
of his status as such, whether or not the corporation would have the power to
indemnify such person against such expense, liability or loss under Chapter 156B
of the Massachusetts General Laws.
 
     11.  Merger or Consolidation.  If the corporation is merged into or
          -----------------------                                       
consolidated with another corporation and the corporation is not the surviving
corporation, the surviving corporation shall assume the obligations of the
corporation under this Article with respect to any action, suit, proceeding or
investigation arising out of or relating to any actions, transactions or facts
occurring prior to the date of such merger or consolidation.
 
     12.  Savings Clause.  If this Article or any portion hereof shall be
          --------------                                                 
invalidated on any ground by any court of competent jurisdiction, then the
corporation shall nevertheless indemnify each Indemnitee as to any expenses
(including attorneys' fees), judgments, fines and amounts paid in settlement in
connection with any action, suit, proceeding or investigation, whether civil,
criminal or administrative, including an action by or in the right of the
corporation, to the fullest extent permitted by any applicable portion of this
Article that shall not have been invalidated and to the fullest extent permitted
by applicable law.
 
     13.  Subsequent Legislation.  If the Massachusetts General Laws are amended
          ----------------------                                                
after adoption of this Article to expand further the indemnification permitted
to Indemnities, then the corporation shall indemnify such persons to the fullest
extent permitted by the Massachusetts General Laws, as so amended.
 
 
6C.  OTHER PROVISIONS
     ----------------
 
     (a)  The directors may make, amend, or repeal the by-laws in whole or in
part, except with respect to any provision of such by-laws which by law or these
Articles of the by-laws requires action by the stockholders.
 
     (b)  Meetings of the stockholders of the corporation may be held anywhere
in the United States.
 
     (c)  The corporation shall have the power to be a partner in any business
enterprise
<PAGE>
 
which this corporation would have the power to conduct by itself.
 
     (d)  The corporation, by vote of a majority of the stock outstanding and
entitled to vote thereon (or if there are two or more classes of stock entitled
to vote as separate classes, then by vote of a majority of each such class of
stock outstanding), may (i) authorize any amendment to its Articles of
Organization pursuant to Section 71 of Chapter 156B of the Massachusetts General
Laws, as amended from time to time, (ii) authorize the sale, lease, or exchange
of all or substantially all of its property and assets, including its goodwill,
pursuant to Section 75 of Chapter 156B of the Massachusetts General Laws, as
amended from time to time, and (iii) approve an agreement of merger or
consolidation pursuant to Section 78 of Chapter 156B of the Massachusetts
General Laws, as amended from time to time.
 
     (e)  The 1987 Massachusetts Control Share Acquisition Act, Chapter 110D of
the Massachusetts General Laws, as it may be amended from time to time, shall
not apply to the corporation.