<PAGE>

        As filed with the Securities and Exchange Commission on June 12, 1997

                                                           REGISTRATION NO. 333-


                          SECURITIES AND EXCHANGE COMMISSION
                               Washington, D. C. 20549

                               -----------------------

                                       FORM S-8

                            REGISTRATION STATEMENT UNDER 
                              THE SECURITIES ACT OF 1933

                               -----------------------


                           GENZYME TRANSGENICS CORPORATION
                (Exact name of registrant as specified in its charter)

                Massachusetts                             04-3186494
       (State or other jurisdiction         (I.R.S. Employer Identification No.)
              of incorporation)


                Five Mountain Road, Framingham, Massachusetts 01701
                      (Address of Principal Executive Offices)



                          1993 EMPLOYEE STOCK PURCHASE PLAN
                               (Full title of the plan)

                                  JAMES A. GERAGHTY
                        President and Chief Executive Officer
                           Genzyme Transgenics Corporation
                                  Five Mountain Road
                           Framingham, Massachusetts 01701
                                    (508) 872-8400
              (Name, address and telephone number of agent for service)

                                   with copies to:

                             LYNNETTE C. FALLON, ESQUIRE
                                  Palmer & Dodge LLP
                                  One Beacon Street
                             Boston, Massachusetts 02108
                                    (617) 573-0100
                                   -----------------
<TABLE>
<CAPTION>
                           CALCULATION OF REGISTRATION FEE
----------------------------------------------------------------------------------------------------------------------------
<S>                                        <C>               <C>                 <C>                   <C>
Title of each class of securities to       Amount to be           Proposed           Proposed maximum         Amount of
          be registered                     registered        maximum offering      aggregate offering    registration fee
                                                              price per share(1)         price(1)
----------------------------------------------------------------------------------------------------------------------------
Common Stock, $0.01 par value              600,000 shares(2)       $8.125               $4,875,000           $1,477.28
----------------------------------------------------------------------------------------------------------------------------
</TABLE>

(1) Estimated solely for the purpose of determining the registration fee and
    computed pursuant to Rule 457(h) and based upon the average of the high and
    low sale prices on June 10, 1997 as reported by the Nasdaq National Market
    System.
(2) This Registration Statement registers an additional 600,000 shares issuable
    under the Registrant's 1993  Employee Stock Purchase Plan (the "Plan"). An
    aggregate of 300,000 shares issuable under the Plan have previously been
    registered (Reg. No. 33-69520 covering 50,000 shares and Reg. No. 33-92970
    covering 250,000 shares).


<PAGE>

              Statement Regarding Incorporation By Reference From
                      Effective Registration Statement.

    Pursuant to Instruction E to Form S-8, the contents of the Registrant's
Registration Statement on Form S-8 filed with the Securities and Exchange
Commission (the "Commission") on September 28, 1993 (File No. 33-69520) relating
to the registration of 50,000 shares of the Registrant's Common Stock, $0.01 par
value per share (the "Common Stock"), authorized for issuance under the
Registrant's 1993 Employee Stock Purchase Plan (the "Plan"), are incorporated by
reference in their entirety in this Registration Statement, except as to the
items set forth below.  This Registration Statement provides for the
registration of an additional 600,000 shares of the Registrant's Common Stock to
be issued under the Plan.

<PAGE>

                                       PART II
                  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


Item 3.  Incorporation of Documents by Reference.

    The following documents filed with the Securities and Exchange Commission
(the "Commission") are incorporated herein by reference:

         (a)  The Registrant's Annual Report on Form 10-K for the fiscal year
ended December 29, 1996.

         (b)  All other reports of the Registrant filed pursuant to Section
13(a) or 15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange
Act"), since the end of the fiscal year covered by the annual report referred to
in (a) above.

         (c)  The description of the Registrant's Common Stock contained in its
Registration Statement on Form 8-A (File No. 0-21794) filed on May 19, 1993,
including any amendment or report filed for the purpose of updating such
description.

    All documents filed after the date of this Registration Statement by the
Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act
and prior to the filing of a post-effective amendment which indicates that all
shares of Common Stock offered hereunder have been sold or which deregisters all
shares of Common Stock remaining unsold shall be deemed to be incorporated by
reference herein and to be a part hereof from the date of the filing of such
reports and documents.


Item 5. Interests of Named Experts and Counsel.

    The validity of the Common Stock offered hereby will be passed upon for the
Company by Palmer & Dodge LLP, Boston, Massachusetts.  Lynnette C. Fallon, the
Assistant Clerk of the Company, is a partner of Palmer & Dodge LLP.


Item 8.  Exhibits.

    See Exhibit Index on page 6.


<PAGE>

                                      SIGNATURES

    Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Boston, Commonwealth of Massachusetts, on this 28th
day of May, 1997.



                             GENZYME TRANSGENICS CORPORATION
                             (Registrant)



                             By: /s/ James A. Geraghty 
                                 -------------------------------------
                                 James A. Geraghty,
                                 President and Chief Executive Officer


                                  POWER OF ATTORNEY
                                           
    We, the undersigned officers and directors of Genzyme Transgenics
Corporation, hereby severally constitute and appoint James A. Geraghty, John B.
Green, Gary Cohen and Lynnette C. Fallon, and each of them singly, our true and
lawful attorneys-in-fact, with full power to them in any and all capacities, to
sign any amendments to this Registration Statement on Form S-8 (including any
post-effective amendments thereto), and to file the same, with exhibits thereto
and other documents in connection therewith, with the Securities and Exchange
Commission, hereby ratifying and confirming all that each of said
attorneys-in-fact may do or cause to be done by virtue hereof.

    Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities stated and on this 28th day of May, 1997:

Signature                              Capacity
---------                              --------


 /s/ James A. Geraghty              President, Chief Executive Officer
------------------------------      (Principal Executive Officer) and Director
James A. Geraghty


 /s/ John B. Green                  Vice President and Chief Financial Officer
------------------------------      (Principal Financial Officer and Principal
 John B. Green                      Accounting Officer)



 /s/ Henri A. Termeer               Chairman of the Board and Director
------------------------------
 Henri A. Termeer


<PAGE>

 /s/ Robert W. Baldridge            Vice Chairman of the Board and Director
------------------------------
Robert W. Baldridge



 /s/ Henry E. Blair                 Director
------------------------------
Henry E. Blair



 /s/ Alan E. Smith                     Director
------------------------------
Alan E. Smith



 /s/ Alan W. Tuck                      Director
------------------------------
Alan W. Tuck



 /s/ Francis J. Bullock                Director
------------------------------
Francis J. Bullock



<PAGE>

                                    EXHIBIT INDEX


Exhibit
Number        Description
-------       -----------
4.1         Restated Articles of Organization of Genzyme Transgenics
            Corporation, as amended.  Filed as Exhibit 3.1 to the
            Registrant's Annual Report on Form 10-K for the year ended
            December 31, 1993 (Commission File No. 0-21794) and
            incorporated herein by reference.

4.2         By-laws of Genzyme Transgenics Corporation (as amended through
            June 25, 1993).  Filed as Exhibit 3.2 to the Registrant's
            Registration Statement on Form S-1 (File No. 33-62782) and
            incorporated herein by
            reference.

5           Opinion of Palmer & Dodge LLP as to the legality of the
            securities registered hereunder.

23.1        Consent of Coopers & Lybrand L.L.P, independent
            accountants.

23.2        Consent of Palmer & Dodge LLP (contained in Opinion
            of Palmer &Dodge LLP filed as Exhibit 5).

24          Power of Attorney (set forth on the Signature Page to
            this Registration Statement).
[{"type": "S-8", "sequence": "1", "description": "S-8", "secsgml_size_bytes": 10191}]
{"company-data": {"conformed-name": "GENZYME TRANSGENICS CORP", "cik": "0000904973", "assigned-sic": "2836", "irs-number": "043186494", "state-of-incorporation": "MA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-29975", "film-number": "97629423"}, "business-address": {"street1": "25 BIRCH STREET", "city": "MILFORD", "state": "MA", "zip": "01757", "phone": "5088728400"}}
As filed with the Securities and Exchange Commission on June 12, 1997

                                                           REGISTRATION NO. 333-

                          SECURITIES AND EXCHANGE COMMISSION
                               Washington, D. C. 20549

                               -----------------------

                                       FORM S-8

                            REGISTRATION STATEMENT UNDER 
                              THE SECURITIES ACT OF 1933

                               -----------------------

                           GENZYME TRANSGENICS CORPORATION
                (Exact name of registrant as specified in its charter)

                Massachusetts                             04-3186494
       (State or other jurisdiction         (I.R.S. Employer Identification No.)
              of incorporation)

                Five Mountain Road, Framingham, Massachusetts 01701
                      (Address of Principal Executive Offices)

                          1993 EMPLOYEE STOCK PURCHASE PLAN
                               (Full title of the plan)

                                  JAMES A. GERAGHTY
                        President and Chief Executive Officer
                           Genzyme Transgenics Corporation
                                  Five Mountain Road
                           Framingham, Massachusetts 01701
                                    (508) 872-8400
              (Name, address and telephone number of agent for service)

                                   with copies to:

                             LYNNETTE C. FALLON, ESQUIRE
                                  Palmer & Dodge LLP
                                  One Beacon Street
                             Boston, Massachusetts 02108
                                    (617) 573-0100
                                   -----------------
CALCULATION OF REGISTRATION FEE
----------------------------------------------------------------------------------------------------------------------------
Title of each class of securities to       Amount to be           Proposed           Proposed maximum         Amount of
          be registered                     registered        maximum offering      aggregate offering    registration fee
                                                              price per share(1)         price(1)
----------------------------------------------------------------------------------------------------------------------------
Common Stock, $0.01 par value              600,000 shares(2)       $8.125               $4,875,000           $1,477.28
----------------------------------------------------------------------------------------------------------------------------
(1) Estimated solely for the purpose of determining the registration fee and
    computed pursuant to Rule 457(h) and based upon the average of the high and
    low sale prices on June 10, 1997 as reported by the Nasdaq National Market
    System.
(2) This Registration Statement registers an additional 600,000 shares issuable
    under the Registrant's 1993  Employee Stock Purchase Plan (the "Plan"). An
    aggregate of 300,000 shares issuable under the Plan have previously been
    registered (Reg. No. 33-69520 covering 50,000 shares and Reg. No. 33-92970
    covering 250,000 shares).
Statement Regarding Incorporation By Reference From
                      Effective Registration Statement.

    Pursuant to Instruction E to Form S-8, the contents of the Registrant's
Registration Statement on Form S-8 filed with the Securities and Exchange
Commission (the "Commission") on September 28, 1993 (File No. 33-69520) relating
to the registration of 50,000 shares of the Registrant's Common Stock, $0.01 par
value per share (the "Common Stock"), authorized for issuance under the
Registrant's 1993 Employee Stock Purchase Plan (the "Plan"), are incorporated by
reference in their entirety in this Registration Statement, except as to the
items set forth below.  This Registration Statement provides for the
registration of an additional 600,000 shares of the Registrant's Common Stock to
be issued under the Plan.
PART II
                  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

    The following documents filed with the Securities and Exchange Commission
(the "Commission") are incorporated herein by reference:

         (a)  The Registrant's Annual Report on Form 10-K for the fiscal year
ended December 29, 1996.

         (b)  All other reports of the Registrant filed pursuant to Section
13(a) or 15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange
Act"), since the end of the fiscal year covered by the annual report referred to
in (a) above.

         (c)  The description of the Registrant's Common Stock contained in its
Registration Statement on Form 8-A (File No. 0-21794) filed on May 19, 1993,
including any amendment or report filed for the purpose of updating such
description.

    All documents filed after the date of this Registration Statement by the
Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act
and prior to the filing of a post-effective amendment which indicates that all
shares of Common Stock offered hereunder have been sold or which deregisters all
shares of Common Stock remaining unsold shall be deemed to be incorporated by
reference herein and to be a part hereof from the date of the filing of such
reports and documents.

Item 5. Interests of Named Experts and Counsel.

    The validity of the Common Stock offered hereby will be passed upon for the
Company by Palmer & Dodge LLP, Boston, Massachusetts.  Lynnette C. Fallon, the
Assistant Clerk of the Company, is a partner of Palmer & Dodge LLP.

Item 8.  Exhibits.

    See Exhibit Index on page 6.
SIGNATURES

    Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Boston, Commonwealth of Massachusetts, on this 28th
day of May, 1997.

                             GENZYME TRANSGENICS CORPORATION
                             (Registrant)

                             By: /s/ James A. Geraghty 
                                 -------------------------------------
                                 James A. Geraghty,
                                 President and Chief Executive Officer

                                  POWER OF ATTORNEY
                                           
    We, the undersigned officers and directors of Genzyme Transgenics
Corporation, hereby severally constitute and appoint James A. Geraghty, John B.
Green, Gary Cohen and Lynnette C. Fallon, and each of them singly, our true and
lawful attorneys-in-fact, with full power to them in any and all capacities, to
sign any amendments to this Registration Statement on Form S-8 (including any
post-effective amendments thereto), and to file the same, with exhibits thereto
and other documents in connection therewith, with the Securities and Exchange
Commission, hereby ratifying and confirming all that each of said
attorneys-in-fact may do or cause to be done by virtue hereof.

    Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities stated and on this 28th day of May, 1997:

Signature                              Capacity
---------                              --------

 /s/ James A. Geraghty              President, Chief Executive Officer
------------------------------      (Principal Executive Officer) and Director
James A. Geraghty

 /s/ John B. Green                  Vice President and Chief Financial Officer
------------------------------      (Principal Financial Officer and Principal
 John B. Green                      Accounting Officer)

 /s/ Henri A. Termeer               Chairman of the Board and Director
------------------------------
 Henri A. Termeer
/s/ Robert W. Baldridge            Vice Chairman of the Board and Director
------------------------------
Robert W. Baldridge

 /s/ Henry E. Blair                 Director
------------------------------
Henry E. Blair

 /s/ Alan E. Smith                     Director
------------------------------
Alan E. Smith

 /s/ Alan W. Tuck                      Director
------------------------------
Alan W. Tuck

 /s/ Francis J. Bullock                Director
------------------------------
Francis J. Bullock
EXHIBIT INDEX

Exhibit
Number        Description
-------       -----------
4.1         Restated Articles of Organization of Genzyme Transgenics
            Corporation, as amended.  Filed as Exhibit 3.1 to the
            Registrant's Annual Report on Form 10-K for the year ended
            December 31, 1993 (Commission File No. 0-21794) and
            incorporated herein by reference.

4.2         By-laws of Genzyme Transgenics Corporation (as amended through
            June 25, 1993).  Filed as Exhibit 3.2 to the Registrant's
            Registration Statement on Form S-1 (File No. 33-62782) and
            incorporated herein by
            reference.

5           Opinion of Palmer & Dodge LLP as to the legality of the
            securities registered hereunder.

23.1        Consent of Coopers & Lybrand L.L.P, independent
            accountants.

23.2        Consent of Palmer & Dodge LLP (contained in Opinion
            of Palmer &Dodge LLP filed as Exhibit 5).

24          Power of Attorney (set forth on the Signature Page to
            this Registration Statement).