WASHINGTON, DC 20549

                                    FORM 8-K

                             CURRENT REPORT PURSUANT
                          TO SECTION 13 OR 15(D) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

     Date of report (Date of earliest event reported)     May 1, 2006

                        Parametric Technology Corporation
             (Exact Name of Registrant as Specified in Its Charter)

                 (State or Other Jurisdiction of Incorporation)

             0-18059                                      04-2866152
    (Commission File Number)                   (IRS Employer Identification No.)

              140 Kendrick Street
             Needham, Massachusetts                       02494-2714
    (Address of Principal Executive Offices)             (Zip Code)

                                 (781) 370-5000
              (Registrant's Telephone Number, Including Area Code)

          (Former Name or Former Address, if Changed Since Last Report)

     Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2. below):

     |_| Written communications pursuant to Rule 425 under the Securities Act
(17 CFR 230.425)

     |_| Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17
CFR 240.14a-12)

     |_| Pre-commencement communications pursuant to Rule 14d-2(b) under the
Exchange Act (17 CFR 240.14d-2(b))

     |_| Pre-commencement communications pursuant to Rule 13e-4(c) under the
Exchange Act (17 CFR 240.13e-4(c))

                            Section 7 - Regulation FD

Item 7.01.  Regulation FD Disclosure.

On April 28, 2006, Parametric Technology Corporation completed its previously
announced acquisition of Mathsoft Corporate Holdings, Inc., including its wholly
owned subsidiary Mathsoft Engineering & Education, Inc. ("Mathsoft"), for
approximately $63.1 million in cash. Mathsoft is the provider of Mathcad(R),
software that helps engineering organizations create, automate, document and
reuse engineering calculations in the product development process, as well as
other mathematics-driven processes.


Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                 Parametric Technology Corporation

Date:  May 1, 2006               By:   /s/ Cornelius F. Moses, III
                                       Cornelius F. Moses, III
                                       Executive Vice President and
                                       Chief Financial Officer