<PAGE>   1
                                          
              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

                           BIOTRANSPLANT INCORPORATED
             (Exact name of registrant as specified in its charter)

       DELAWARE                                                 04-3119555
(State or other jurisdiction of                              (I.R.S. Employer
incorporation or organization)                            Identification Number)

         CHARLESTOWN NAVY YARD
       BUILDING 75, THIRD AVENUE
       CHARLESTOWN, MASSACHUSETTS                                  02129
(Address of Principal Executive Offices)                        (Zip Code)

                            1997 STOCK INCENTIVE PLAN
                            (Full title of the Plan)

                             ELLIOT LEBOWITZ, PH.D.
                      PRESIDENT AND CHIEF EXECUTIVE OFFICER
                           BIOTRANSPLANT INCORPORATED
                              CHARLESTOWN NAVY YARD
                            BUILDING 75, THIRD AVENUE
                        CHARLESTOWN, MASSACHUSETTS 02129
                     (Name and address of agent for service)
                                 (617) 241-5200
          (Telephone number, including area code, of agent for service)

================================================================================

<TABLE>
                         CALCULATION OF REGISTRATION FEE
<CAPTION>

                                  Proposed       Proposed
Title of                          maximum        maximum
securities        Amount          offering       aggregate        Amount of
to be             to be           price          offering         registration
registered        registered      per share      price            fee
----------        ----------      ---------      ---------        ------------
                                            
<S>               <C>              <C>         <C>                 <C>
Common            750,000          $6.75(1)    $5,062,500.00(1)    1,535.00
Stock,            shares  
$0.01 par
value per share
--------------------------------------------------------------------------------
</TABLE>
(1)  Estimated solely for the purpose of calculating the registration fee and
     based upon the average of the high and low trading prices of the
     Registrant's Common Stock, as reported on the Nasdaq National Market on
     June 6, 1997, in accordance with Rules 457(c) and 457(h) of the Securities
     Act of 1933, as amended.

================================================================================




<PAGE>   2

PART I.  INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

                  The information required by Part I of Form S-8 is included in
documents sent or given to participants in the 1997 Stock Incentive Plan of
BioTransplant Incorporated, a Delaware corporation (the "Registrant"), pursuant
to Rule 428(b)(1) of the Securities Act of 1933, as amended (the "Securities
Act").


PART II.  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

         Item 3.  INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

                  The following documents, which are filed with the Securities
and Exchange Commission (the "Commission"), are incorporated in this
Registration Statement by reference:

                  (1) The Registrant's latest annual report filed pursuant to
         Sections 13(a) or 15(d) of the Securities Exchange Act of 1934, as 
         amended (the "Exchange Act"), or the latest prospectus filed pursuant
         to Rule 424(b) under the Securities Act that contains audited financial
         statements for the Registrant's latest fiscal year for which such
         statements have been filed.

                  (2) All other reports filed pursuant to Sections 13(a) or
         15(d) of the Exchange Act since the end of the fiscal year covered by 
         the prospectus referred to in (1) above.

                  (3) The description of the Common Stock of the Registrant,
         $0.01 par value per share (the "Common Stock"), contained in the
         Registrant's Registration Statement on Form 8-A filed under the 
         Exchange Act, including any amendment or report filed for the purpose
         of updating such information.

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


         Item 4.  DESCRIPTION OF SECURITIES

                  Not applicable.


         Item 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

                  Not applicable.


                                      -2-
<PAGE>   3


         Item 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

                  Section 145 of the General Corporation Law of Delaware
provides that a corporation has the power to indemnify a director, officer,
employee or agent of the corporation and certain other persons serving at the
request of the corporation in related capacities against amounts paid and
expenses incurred in connection with an action or proceeding to which such
person is or is threatened to be made a party by reason of such position, if
such person shall have acted in good faith and in a manner reasonably believed
to be in or not opposed to the best interests of the corporation, and, in any
criminal proceeding, if such person had no reasonable cause to believe such
conduct was unlawful; provided that, in the case of actions brought by or in the
right of the corporation, no indemnification shall be made with respect to any
matter as to which such person shall have been adjudged to be liable to the
corporation unless and only to the extent that the adjudicating court determines
that such indemnification is proper under the circumstances.

                  Article X of the Registrant's Certificate of Incorporation
provides that a director or officer of the Registrant (a) shall be indemnified
by the Registrant against all expenses (including attorney's fees), judgments,
fines and amounts paid in settlement reasonably incurred in connection with any
litigation or other legal proceeding (other than an action by or in the right of
the Registrant) brought against such director or officer by virtue of a position
as a director or officer of the Registrant if such director or officer acted in
good faith and in a manner reasonably believed by such director to be in or not
opposed to the best interests of the Registrant, and, with respect to any
criminal action or proceeding, such director had no reasonable cause to believe
such conduct was unlawful and (b) shall be indemnified by the Registrant against
expenses (including attorneys' fees) and amounts paid in settlement reasonably
incurred in connection with any action by or in the right of the Registrant by
virtue of a position as a director or officer of the Registrant if such officer
or director acted in good faith and in a manner reasonably believed to be in or
not opposed to the best interests of the Registrant, except that no
indemnification shall be made with respect to any such matter as to which such
director or officer shall have been adjudged to be liable to the Registrant,
unless and only to the extent that a court determines that, despite the
adjudication of liability but in view of all the circumstances of the case, such
person is fairly and reasonably entitled to indemnity for such expenses as the
court deems proper. Nothwithstanding the foregoing, to the extent that a
director or officer has been successful, on the merits or otherwise, such person
shall be indemnified against all expenses (including attorney's fees) reasonably
incurred in connection therewith. 


                                      -3-
<PAGE>   4

Expenses incurred in defending a civil or criminal action, suit or proceeding
shall be advanced by the Registrant to a director or officer, at such person's
request, upon receipt of an undertaking by the director or officer to repay such
amount if it is ultimately determined that such person is not entitled to
indemnification.

                  Indemnification is required to be made unless the Registrant
determines that the applicable standard of conduct required for indemnification
has not been met. In the event of a determination by the Registrant that the
director or officer did not meet applicable standard of conduct required for
indemnification, or if the Registrant fails to make an indemnification payment
within 60 days after such payment is claimed by such person, such person is
permitted to petition a court to make an independent determination as to whether
such person is entitled to indemnification. As a condition precedent to the
right of indemnification, the director or officer must give the Registrant
notice of the action for which indemnity is sought and the Registrant has the
right to participate in such action or assume the defense thereof.

                  Article X of the Registrant's Certificate of Incorporation
further provides that the indemnification provided therein is not exclusive, and
provides that in the event that the Delaware General Corporation Law is amended
to expand the indemnification permitted to directors or officers, the Registrant
must indemnify those persons to the fullest extent permitted by such law as so
amended.

                  Article IX of the Registrant's Certificate of Incorporation
provides that, except to the extent that the General Corporation Law of Delaware
prohibits the elimination or limitation of liability of directors for breaches
of fiduciary duty, no director of the Registrant shall be personally liable to
the Registrant or its stockholders for monetary damages for any breach of
fiduciary duty as a director.

                  The Registrant has purchased a general liability insurance
policy which covers certain liabilities of directors and officers of the
Registrant arising out of claims based on acts or omissions in their capacity as
directors or officers.

         Item 7.  EXEMPTION FROM REGISTRATION CLAIMED

                  Not applicable.


         Item 8.  EXHIBITS

                  The Exhibit Index immediately preceding the exhibits is
incorporated herein by reference.


                                      -4-

<PAGE>   5

         Item 9.  UNDERTAKINGS

         1.   The Registrant hereby undertakes:

              (a)    To file, during any period in which offers or sales are 
         being made, a post-effective amendment to this Registration Statement:

              (i)    To include any prospectus required by Section 10(a)(3) of
                     the Securities Act;

              (ii)   To reflect in the prospectus any facts or events arising
                     after the effective date of the Registration Statement (or
                     the most recent post-effective amendment thereof) which,
                     individually or in the aggregate, represent a fundamental
                     change in the information set forth in the Registration
                     Statement; and

              (iii)  To include any material information with respect to the
                     plan of distribution not previously disclosed in the
                     Registration Statement or any material change to such
                     information in the Registration Statement;

         PROVIDED, HOWEVER, that paragraphs (i) and (ii) do not apply if the
         Registration Statement is on Form S-3 or Form S-8, and the information
         required to be included in a post-effective amendment by those
         paragraphs is contained in periodic reports filed by the Registrant
         pursuant to Section 13 or Section 15(d) of the Exchange Act that are
         incorporated by reference in the Registration Statement.

              (b)    That, for the purpose of determining any liability under
         the Securities Act, each such post-effective amendment shall be deemed
         to be a new Registration Statement relating to the securities offered
         therein, and the offering of such securities at that time shall be
         deemed to be the initial bona fide offering thereof.

              (c)    To remove from registration by means of a post-effective
         amendment any of the securities being registered which remain unsold at
         the termination of the offering.

         2. The Registrant hereby undertakes that, for purposes of determining
any liability under the Securities Act, each filing of the Registrant's annual
report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and,
where applicable, each filing of an employee benefit plan's annual report
pursuant to Section 15(d) of the Exchange Act) that is incorporated by 


                                      -5-
<PAGE>   6

reference in the Registration Statement shall be deemed to be a new Registration
Statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial bona fide offering
thereof.

         3. Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.


                                      -6-

<PAGE>   7


                                   SIGNATURES

         Pursuant to the requirements of the Securities Act, 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 Town of Charlestown, Commonwealth of Massachusetts, this 10th
day of June, 1997.


                                          BioTransplant Incorporated




                                          By: /s/ Elliot Lebowitz
                                             -----------------------------------
                                             Elliot Lebowitz
                                             President and
                                             Chief Executive Officer




                                POWER OF ATTORNEY

         We, the undersigned officers and directors of BioTransplant
Incorporated, hereby severally constitute and appoint Elliot Lebowitz, Richard
V. Capasso and Steven D. Singer, and each of them singly, our true and lawful
attorneys with full power to them, and each of them singly, to sign for us and
in our names, in the capacities indicated below, the Registration Statement on
Form S-8 filed herewith, and any and all subsequent amendments to said
Registration Statement, and generally to do all such things in our names and on
our behalf and in our capacities as officers and directors to enable
BioTransplant Incorporated to comply with the provisions of the Securities Act
of 1933, as amended, and all requirements of the Securities and Exchange
Commission, hereby ratifying and confirming our signatures as they may be signed
by our said attorneys, or any of them, to said Registration Statement and any
and all amendments thereto.


                                      -7-
<PAGE>   8


         Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed below by the following persons in the capacities and
on the dates indicated.


          Signature                        Title                   Date
          ---------                        -----                   ----

/s/ Elliot Lebowitz                 President, Chief            June 10, 1997
-----------------------------         Executive Officer
Elliot Lebowitz                       and Director
                                      (Principal
                                      Executive
                                      Officer)

/s/ Richard V. Capasso              Vice President,             June 10, 1997
-----------------------------         Finance (Principal
Richard V. Capasso                    Financial and
                                      Accounting Officer)

/s/ Donald R. Conklin               Director                    June 10, 1997
-----------------------------                                  
Donald R. Conklin                                              
                                                               
/s/ William W. Crouse               Director                    June 10, 1997
-----------------------------                                  
William W. Crouse                                              
                                                               
/s/ James C. Foster                 Director                    June 10, 1997
-----------------------------                                  
James C. Foster                                                
                                                               
/s/ Daniel O. Hauser                Director                    June 10, 1997
-----------------------------                                  
Daniel O. Hauser                                               
                                                               
/s/ Robert A. Vukovich              Director                    June 10, 1997
-----------------------------                                  
Robert A. Vukovich                                             
                                                               
                                    Director                    June   , 1997
-----------------------------
Daniel P. Kearney


                                      -8-
<PAGE>   9




                                  Exhibit Index


Exhibit
Number            Description
-------           -----------

   4.1 (1)        Restated Certificate of Incorporation,
                  as amended to date.

   4.2 (1)        By-laws, as amended to date

   4.3 (1)        Specimen Certificate of Common Stock,
                  $0.01 par value, of the Registrant

   5              Opinion of Hale and Dorr LLP

  23.1            Consent of Hale and Dorr LLP
                  (included in Exhibit 5)

  23.2            Consent of Arthur Andersen LLP

  24              Power of Attorney (included on the signature
                  page of this Registration Statement)



--------

   (1) Incorporated herein by reference to the Registrant's Registration 
       Statement on Form S-1 (File No. 333-2144).
[{"type": "S-8", "sequence": "1", "description": "BIOTRANSPLANT, INC. 1997 STOCK INCENTIVE PLAN", "secsgml_size_bytes": 20301}]
{"company-data": {"conformed-name": "BIOTRANSPLANT INC", "cik": "0000880259", "assigned-sic": "2834", "irs-number": "043119555", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-29055", "film-number": "97623062"}, "business-address": {"street1": "BUILDING 75, 3RD AVENUE", "street2": "BLDG 96 13TH ST", "city": "CHARLESTOWN", "state": "MA", "zip": "02129", "phone": "6172415200"}}
1
                                          
              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

                           BIOTRANSPLANT INCORPORATED
             (Exact name of registrant as specified in its charter)

       DELAWARE                                                 04-3119555
(State or other jurisdiction of                              (I.R.S. Employer
incorporation or organization)                            Identification Number)

         CHARLESTOWN NAVY YARD
       BUILDING 75, THIRD AVENUE
       CHARLESTOWN, MASSACHUSETTS                                  02129
(Address of Principal Executive Offices)                        (Zip Code)

                            1997 STOCK INCENTIVE PLAN
                            (Full title of the Plan)

                             ELLIOT LEBOWITZ, PH.D.
                      PRESIDENT AND CHIEF EXECUTIVE OFFICER
                           BIOTRANSPLANT INCORPORATED
                              CHARLESTOWN NAVY YARD
                            BUILDING 75, THIRD AVENUE
                        CHARLESTOWN, MASSACHUSETTS 02129
                     (Name and address of agent for service)
                                 (617) 241-5200
          (Telephone number, including area code, of agent for service)

================================================================================

                         CALCULATION OF REGISTRATION FEE
Proposed       Proposed
Title of                          maximum        maximum
securities        Amount          offering       aggregate        Amount of
to be             to be           price          offering         registration
registered        registered      per share      price            fee
----------        ----------      ---------      ---------        ------------
Common            750,000          $6.75(1)    $5,062,500.00(1)    1,535.00
Stock,            shares  
$0.01 par
value per share
--------------------------------------------------------------------------------
(1)  Estimated solely for the purpose of calculating the registration fee and
     based upon the average of the high and low trading prices of the
     Registrant's Common Stock, as reported on the Nasdaq National Market on
     June 6, 1997, in accordance with Rules 457(c) and 457(h) of the Securities
     Act of 1933, as amended.

================================================================================
2

PART I.  INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

                  The information required by Part I of Form S-8 is included in
documents sent or given to participants in the 1997 Stock Incentive Plan of
BioTransplant Incorporated, a Delaware corporation (the "Registrant"), pursuant
to Rule 428(b)(1) of the Securities Act of 1933, as amended (the "Securities
Act").

PART II.  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

         Item 3.  INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

                  The following documents, which are filed with the Securities
and Exchange Commission (the "Commission"), are incorporated in this
Registration Statement by reference:

                  (1) The Registrant's latest annual report filed pursuant to
         Sections 13(a) or 15(d) of the Securities Exchange Act of 1934, as 
         amended (the "Exchange Act"), or the latest prospectus filed pursuant
         to Rule 424(b) under the Securities Act that contains audited financial
         statements for the Registrant's latest fiscal year for which such
         statements have been filed.

                  (2) All other reports filed pursuant to Sections 13(a) or
         15(d) of the Exchange Act since the end of the fiscal year covered by 
         the prospectus referred to in (1) above.

                  (3) The description of the Common Stock of the Registrant,
         $0.01 par value per share (the "Common Stock"), contained in the
         Registrant's Registration Statement on Form 8-A filed under the 
         Exchange Act, including any amendment or report filed for the purpose
         of updating such information.

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

         Item 4.  DESCRIPTION OF SECURITIES

                  Not applicable.

         Item 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

                  Not applicable.

                                      -2-
3

         Item 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

                  Section 145 of the General Corporation Law of Delaware
provides that a corporation has the power to indemnify a director, officer,
employee or agent of the corporation and certain other persons serving at the
request of the corporation in related capacities against amounts paid and
expenses incurred in connection with an action or proceeding to which such
person is or is threatened to be made a party by reason of such position, if
such person shall have acted in good faith and in a manner reasonably believed
to be in or not opposed to the best interests of the corporation, and, in any
criminal proceeding, if such person had no reasonable cause to believe such
conduct was unlawful; provided that, in the case of actions brought by or in the
right of the corporation, no indemnification shall be made with respect to any
matter as to which such person shall have been adjudged to be liable to the
corporation unless and only to the extent that the adjudicating court determines
that such indemnification is proper under the circumstances.

                  Article X of the Registrant's Certificate of Incorporation
provides that a director or officer of the Registrant (a) shall be indemnified
by the Registrant against all expenses (including attorney's fees), judgments,
fines and amounts paid in settlement reasonably incurred in connection with any
litigation or other legal proceeding (other than an action by or in the right of
the Registrant) brought against such director or officer by virtue of a position
as a director or officer of the Registrant if such director or officer acted in
good faith and in a manner reasonably believed by such director to be in or not
opposed to the best interests of the Registrant, and, with respect to any
criminal action or proceeding, such director had no reasonable cause to believe
such conduct was unlawful and (b) shall be indemnified by the Registrant against
expenses (including attorneys' fees) and amounts paid in settlement reasonably
incurred in connection with any action by or in the right of the Registrant by
virtue of a position as a director or officer of the Registrant if such officer
or director acted in good faith and in a manner reasonably believed to be in or
not opposed to the best interests of the Registrant, except that no
indemnification shall be made with respect to any such matter as to which such
director or officer shall have been adjudged to be liable to the Registrant,
unless and only to the extent that a court determines that, despite the
adjudication of liability but in view of all the circumstances of the case, such
person is fairly and reasonably entitled to indemnity for such expenses as the
court deems proper. Nothwithstanding the foregoing, to the extent that a
director or officer has been successful, on the merits or otherwise, such person
shall be indemnified against all expenses (including attorney's fees) reasonably
incurred in connection therewith. 

                                      -3-
4

Expenses incurred in defending a civil or criminal action, suit or proceeding
shall be advanced by the Registrant to a director or officer, at such person's
request, upon receipt of an undertaking by the director or officer to repay such
amount if it is ultimately determined that such person is not entitled to
indemnification.

                  Indemnification is required to be made unless the Registrant
determines that the applicable standard of conduct required for indemnification
has not been met. In the event of a determination by the Registrant that the
director or officer did not meet applicable standard of conduct required for
indemnification, or if the Registrant fails to make an indemnification payment
within 60 days after such payment is claimed by such person, such person is
permitted to petition a court to make an independent determination as to whether
such person is entitled to indemnification. As a condition precedent to the
right of indemnification, the director or officer must give the Registrant
notice of the action for which indemnity is sought and the Registrant has the
right to participate in such action or assume the defense thereof.

                  Article X of the Registrant's Certificate of Incorporation
further provides that the indemnification provided therein is not exclusive, and
provides that in the event that the Delaware General Corporation Law is amended
to expand the indemnification permitted to directors or officers, the Registrant
must indemnify those persons to the fullest extent permitted by such law as so
amended.

                  Article IX of the Registrant's Certificate of Incorporation
provides that, except to the extent that the General Corporation Law of Delaware
prohibits the elimination or limitation of liability of directors for breaches
of fiduciary duty, no director of the Registrant shall be personally liable to
the Registrant or its stockholders for monetary damages for any breach of
fiduciary duty as a director.

                  The Registrant has purchased a general liability insurance
policy which covers certain liabilities of directors and officers of the
Registrant arising out of claims based on acts or omissions in their capacity as
directors or officers.

         Item 7.  EXEMPTION FROM REGISTRATION CLAIMED

                  Not applicable.

         Item 8.  EXHIBITS

                  The Exhibit Index immediately preceding the exhibits is
incorporated herein by reference.

                                      -4-
5

         Item 9.  UNDERTAKINGS

         1.   The Registrant hereby undertakes:

              (a)    To file, during any period in which offers or sales are 
         being made, a post-effective amendment to this Registration Statement:

              (i)    To include any prospectus required by Section 10(a)(3) of
                     the Securities Act;

              (ii)   To reflect in the prospectus any facts or events arising
                     after the effective date of the Registration Statement (or
                     the most recent post-effective amendment thereof) which,
                     individually or in the aggregate, represent a fundamental
                     change in the information set forth in the Registration
                     Statement; and

              (iii)  To include any material information with respect to the
                     plan of distribution not previously disclosed in the
                     Registration Statement or any material change to such
                     information in the Registration Statement;

         PROVIDED, HOWEVER, that paragraphs (i) and (ii) do not apply if the
         Registration Statement is on Form S-3 or Form S-8, and the information
         required to be included in a post-effective amendment by those
         paragraphs is contained in periodic reports filed by the Registrant
         pursuant to Section 13 or Section 15(d) of the Exchange Act that are
         incorporated by reference in the Registration Statement.

              (b)    That, for the purpose of determining any liability under
         the Securities Act, each such post-effective amendment shall be deemed
         to be a new Registration Statement relating to the securities offered
         therein, and the offering of such securities at that time shall be
         deemed to be the initial bona fide offering thereof.

              (c)    To remove from registration by means of a post-effective
         amendment any of the securities being registered which remain unsold at
         the termination of the offering.

         2. The Registrant hereby undertakes that, for purposes of determining
any liability under the Securities Act, each filing of the Registrant's annual
report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and,
where applicable, each filing of an employee benefit plan's annual report
pursuant to Section 15(d) of the Exchange Act) that is incorporated by 

                                      -5-
6

reference in the Registration Statement shall be deemed to be a new Registration
Statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial bona fide offering
thereof.

         3. Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.

                                      -6-
7

                                   SIGNATURES

         Pursuant to the requirements of the Securities Act, 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 Town of Charlestown, Commonwealth of Massachusetts, this 10th
day of June, 1997.

                                          BioTransplant Incorporated

                                          By: /s/ Elliot Lebowitz
                                             -----------------------------------
                                             Elliot Lebowitz
                                             President and
                                             Chief Executive Officer

                                POWER OF ATTORNEY

         We, the undersigned officers and directors of BioTransplant
Incorporated, hereby severally constitute and appoint Elliot Lebowitz, Richard
V. Capasso and Steven D. Singer, and each of them singly, our true and lawful
attorneys with full power to them, and each of them singly, to sign for us and
in our names, in the capacities indicated below, the Registration Statement on
Form S-8 filed herewith, and any and all subsequent amendments to said
Registration Statement, and generally to do all such things in our names and on
our behalf and in our capacities as officers and directors to enable
BioTransplant Incorporated to comply with the provisions of the Securities Act
of 1933, as amended, and all requirements of the Securities and Exchange
Commission, hereby ratifying and confirming our signatures as they may be signed
by our said attorneys, or any of them, to said Registration Statement and any
and all amendments thereto.

                                      -7-
8

         Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed below by the following persons in the capacities and
on the dates indicated.

          Signature                        Title                   Date
          ---------                        -----                   ----

/s/ Elliot Lebowitz                 President, Chief            June 10, 1997
-----------------------------         Executive Officer
Elliot Lebowitz                       and Director
                                      (Principal
                                      Executive
                                      Officer)

/s/ Richard V. Capasso              Vice President,             June 10, 1997
-----------------------------         Finance (Principal
Richard V. Capasso                    Financial and
                                      Accounting Officer)

/s/ Donald R. Conklin               Director                    June 10, 1997
-----------------------------                                  
Donald R. Conklin                                              
                                                               
/s/ William W. Crouse               Director                    June 10, 1997
-----------------------------                                  
William W. Crouse                                              
                                                               
/s/ James C. Foster                 Director                    June 10, 1997
-----------------------------                                  
James C. Foster                                                
                                                               
/s/ Daniel O. Hauser                Director                    June 10, 1997
-----------------------------                                  
Daniel O. Hauser                                               
                                                               
/s/ Robert A. Vukovich              Director                    June 10, 1997
-----------------------------                                  
Robert A. Vukovich                                             
                                                               
                                    Director                    June   , 1997
-----------------------------
Daniel P. Kearney

                                      -8-
9

                                  Exhibit Index

Exhibit
Number            Description
-------           -----------

   4.1 (1)        Restated Certificate of Incorporation,
                  as amended to date.

   4.2 (1)        By-laws, as amended to date

   4.3 (1)        Specimen Certificate of Common Stock,
                  $0.01 par value, of the Registrant

   5              Opinion of Hale and Dorr LLP

  23.1            Consent of Hale and Dorr LLP
                  (included in Exhibit 5)

  23.2            Consent of Arthur Andersen LLP

  24              Power of Attorney (included on the signature
                  page of this Registration Statement)

--------

   (1) Incorporated herein by reference to the Registrant's Registration 
       Statement on Form S-1 (File No. 333-2144).