1
      As filed with the Securities and Exchange Commission on June 25, 1996

                                                      REGISTRATION NO. 333-


                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D. C. 20549

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

                                    FORM S-8

                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

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

                          GELTEX PHARMACEUTICALS, INC.
             (Exact name of registrant as specified in its charter)


          DELAWARE                                           04-3136767
(State or other jurisdiction                              (I.R.S. Employer 
      of incorporation)                                  Identification No.)

         303 BEAR HILL ROAD, WALTHAM, MASSACHUSETTS 02154 (617) 290-5888
   (Address and telephone number of registrant's principal executive offices)
                              ---------------------

                         1995 DIRECTOR STOCK OPTION PLAN
                            (Full Title of the Plan)

              MARK SKALETSKY, PRESIDENT AND CHIEF EXECUTIVE OFFICER
                          GelTex Pharmaceuticals, Inc.
                               303 Bear Hill Road
                          Waltham, Massachusetts 02154
                                 (617) 290-5888
            (Name, address and telephone number of agent for service)

                                 with copies to:

                              PETER WIRTH, 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              price
- -------------------------------------------------------------------------------------------------------------------------------
                                                                                                           
Common Stock, $0.01 par value          52,000 shares(1)            $11.25(2)             $585,000.00(2)            $202.00
- -------------------------------------------------------------------------------------------------------------------------------
Common Stock, $0.01 par value          23,000 shares              $21.125(3)             $485,875.00(3)            $168.00
- -------------------------------------------------------------------------------------------------------------------------------


(1)  Shares subject to outstanding options.
(2)  Computed in accordance with Rule 457(h)(1) based on the price per share at
     which currently outstanding options may be exercised.
(3)  Estimated solely for the purpose of determining the registration fee and
     computed pursuant to Rule 457(h) based upon the average of the high and low
     sale prices on June 19, 1996 as reported by the Nasdaq National Market
     System.

                                  Page 1 of 23
                         Exhibit Index appears at Page 8
   2
                                     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 31, 1995 (File No. 0-26872) filed with the Commission on March
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. 0-26872) filed with the Commission
on September 26, 1995, as amended on October 12, 1995, including any amendment
or report filed hereafter for the purpose of updating such description.

         All documents filed after the date of this Registration Statement by
the Registrant pursuant to Section 13(a), 13(d), 14 and 15(d) of the Exchange
Act and prior to the filing of a post-effective amendment that 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 4.  Description of Securities.

         Not applicable.

Item 5.  Interests of Named Experts and Counsel.

         The validity of the Common Stock offered hereby will be passed upon for
the Registrant by Palmer & Dodge LLP, Boston, Massachusetts. Peter Wirth, a
partner of Palmer & Dodge LLP, is Secretary of the Registrant.

Item 6. Indemnification of Directors and Officers

         Section 145 of the Delaware General Corporation Law permits the
Registrant to indemnify directors, officers, employees and agents of the
Registrant against actual and reasonable expenses (including attorneys' fees)
incurred by them in connection with any action, suit or proceeding brought
against them by reason of their status or service as a director, officer,
employee or agent by or on behalf of the Registrant, and against expenses
(including attorneys' fees), judgments, fines and settlements actually and
reasonably incurred by him in connection with any such action, suit or
proceeding, if (i) he acted in good faith and in a manner he reasonably believed
to be in or not opposed to the best interests of the Registrant, and (ii) in the
case of a criminal proceeding, he had no reasonable cause to believe his


                                      - 2 -
   3
conduct was unlawful. Except as ordered by a court, no indemnification shall be
made in connection with any proceeding brought by or in the right of the
corporation where the person involved is adjudged to be liable to the
Registrant.

         Article EIGHTH of the Registrant's Restated Certificate of
Incorporation provides that a director shall not be personally liable to the
Registrant or its stockholders for monetary damages for breach of fiduciary duty
as a director, except to the extent that elimination or limitation of liability
is not permitted under the Delaware General Corporation Law as in effect when
such liability is determined.

         Article NINTH of the Registrant's Restated Certificate of Incorporation
provides that the Registrant shall, to the fullest extent permitted by the
General Corporation Law of the State of Delaware, as amended from time to time,
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 Registrant, or
is or was serving, or has agreed to serve at the request of the Registrant as a
director, officer or trustee of, or in a similar capacity with, another
corporation, partnership, joint venture, trust or other enterprise. The
indemnification provided for in Article NINTH is expressly not exclusive of any
other rights to which those seeking indemnification may be entitled under any
law, agreement or vote of stockholders or disinterested directors or otherwise,
and shall inure to the benefit of the heirs, executors and administrators of
such persons. Article NINTH further permits the Board of Directors to authorize
the grant of indemnification rights to other employees and agents of the
Registrant and such rights may be equivalent to, or greater or less than, those
set forth in Article NINTH.

         Article V, Section 1 of the Registrant's By-Laws provides that the
Registrant shall have the power to purchase and maintain insurance on behalf of
any person who is or was a director, officer, employee or agent of the
Registrant, or is or was serving at the request of the Registrant as a director,
officer, employee or agent of another corporation, partnership, joint venture,
trust or other enterprise against any liability asserted against such person and
incurred by such person in any such capacity or arising out of such person's
status as such.

         The Registrant maintains insurance for directors and officers and
expects to enter into agreements with certain officers and directors affirming
the Registrant's obligation to indemnify them to the fullest extent permitted by
law and providing various other protections.

Item 7. Exemption from Registration Claimed.

         Not applicable.


                                      - 3 -
   4
Item 8. Exhibits.



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

                                                
        4.1          Restated Certificate of Incorporation of the Registrant.

        4.2          Amended and Restated By-laws of the Registrant.  Filed as Exhibit 3.3 to
                     the Company's Annual Report on Form 10-K for the fiscal year ended
                     December 31, 1995 and incorporated herein by reference.

        4.3          Rights Agreement dated as of March 1, 1996 between the Company and
                     American Stock Transfer & Trust Company.  Filed as Exhibit 1 to the
                     Company's Registration Statement on Form 8-A dated March 1, 1996 and
                     incorporated herein by reference.

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

       23.1          Consent of Ernst & Young LLP, independent auditors.

       23.2          Consent of Palmer & Dodge LLP (contained in Opinion of Palmer &
                     Dodge LLP, filed as Exhibit 5.1 hereto).

       24.1          Power of Attorney (set forth on the signature page to this Registration
                     Statement).

       24.2          Certified resolution of the Board of Directors authorizing Power of
                     Attorney.

       99.1          1995 Director Stock Option Plan.  Filed as Exhibit 10.22 to the
                     Company's Annual Report on Form 10-K for the fiscal year ended
                     December 31, 1995 and incorporated herein by reference.

       99.2          Form of 1995 Director Stock Option Plan Nonstatutory Stock Option
                     Certificate.


Item 9.  Undertakings.

         (a)  The undersigned Registrant hereby undertakes:

              (1)  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 of 1933;

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


                                      - 4 -
   5
                 (iii)  To include any material information with respect to the
plan of distribution not previously disclosed in this Registration Statement or
any material change to such information in this Registration Statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if 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 Securities Exchange Act of 1934 that are
incorporated by reference in this Registration Statement.

              (2)  That, for the purpose of determining any liability under the
Securities Act of 1933, 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.

              (3)  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.

         (b)  The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934 that is incorporated by reference in this
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.

         (c)  Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the Registrant pursuant to the provisions referred to in Item 6
hereof, 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 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 Act and
will be governed by the final adjudication of such issue.


                                      - 5 -
   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 Waltham, State of Massachusetts, on this 25th day of
June, 1996.

                                  GELTEX PHARMACEUTICALS, INC.



                                  By: /s/ Mark Skaletsky
                                      ------------------------------------------
                                       Mark Skaletsky
                                       President and Chief Executive Officer

                                POWER OF ATTORNEY

         We, the undersigned officers and directors of GelTex Pharmaceuticals,
Inc. hereby severally constitute and appoint Mark Skaletsky and Peter Wirth, 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 and all 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 and on the dates indicated:



       SIGNATURE                    TITLE                                  DATE
       ---------                    -----                                  ---- 

                                                                      
/s/ Mark Skaletsky                  President, Chief Executive             June 25, 1996
- -----------------------------       Officer and Treasurer                
Mark Skaletsky                      (Principal Executive                 
                                    Officer, Principal Financial Officer 
                                    and Principal Accounting Officer)    
                                    

/s/ Robert J. Carpenter             Chairman of the Board                  June 25, 1996
- -----------------------------       and Director 
Robert J. Carpenter                 

/s/ Ernest Parizeau                 Director                               June 25, 1996
- -----------------------------
Ernest Parizeau



                                      - 6 -
   7


       SIGNATURE                    TITLE                      DATE
       ---------                    -----                      ---- 

                                                          
/s/ Barbara A. Piette               Director                   June 25, 1996
- -----------------------------
Barbara A. Piette

/s/ James Tananbaum                 Director                   June 25, 1996
- -----------------------------
James Tananbaum

/s/ Henri A. Termeer                Director                   June 25, 1996
- -----------------------------
Henri A. Termeer

/s/ Jesse Treu                      Director                   June 25, 1996
- -----------------------------
Jesse Treu

/s/ George Whitesides               Director                   June 25, 1996
- -----------------------------
George Whitesides



                                      - 7 -
   8
                                  EXHIBIT INDEX




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

                                                                                         
      4.1             Restated Certificate of Incorporation of the Registrant.                      9

      4.2             Amended and Restated By-laws of the Registrant.                               *
                      Filed as Exhibit 3.3 to the Company's Annual Report
                      on Form 10-K for the fiscal year ended December 31,
                      1995.

      4.3             Rights Agreement dated as of March 1, 1996 between                            *
                      the Company and American Stock Transfer & Trust
                      Company.  Filed as Exhibit 1 to the Company's
                      Registration Statement on Form 8-A dated March 1,
                      1996.

      5.1             Opinion of Palmer & Dodge LLP as to the legality of                          19
                      the securities registered hereunder.

     23.1             Consent of Ernst & Young LLP, independent auditors.                          20

     23.2             Consent of Palmer & Dodge LLP (contained in                                  --
                      Opinion of Palmer & Dodge LLP, filed as Exhibit 5.1
                      hereto).

     24.1             Power of Attorney (set forth on the signature page to                        --
                      this Registration Statement).

     24.2             Certified resolution of the Board of Directors                               21
                      authorizing Power of Attorney.

     99.1             1995 Director Stock Option Plan.  Filed as Exhibit                            *
                      10.22 to the Company's Annual Report on Form 10-K
                      for the fiscal year ended December 31, 1995.

     99.2             Form of 1995 Director Stock Option Plan Nonstatutory                         22
                      Stock Option Certificate.




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

*  Incorporated herein by reference.


                                      - 8 -