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        As filed with the Securities and Exchange Commission on November 2, 1999
                                                      Registration No. 333-83989
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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

                        POST-EFFECTIVE AMENDMENT NO. 1 TO
                                    FORM S-8
                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

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

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


                                         
        Delaware                                         94-2345624
(State of Incorporation)                    (I.R.S. Employer Identification No.)



                                    1 DNA Way
                         South San Francisco, California         94080-4990
                    (Address of principal executive offices)     (Zip Code)

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

                                1999 Stock Plan
                            1991 Employee Stock Plan
                           (Full titles of the plans)


                           Stephen G. Juelsgaard, Esq.
              Senior Vice President, General Counsel and Secretary
                                 Genentech, Inc.
                                    1 DNA Way
                   South San Francisco, California 94080-4990
                     (Name and address of agent for service)



                                 (650) 225-1000
          (Telephone number, including area code, of agent for service)




                                            CALCULATION OF REGISTRATION FEE
=======================================================================================================================
                                                       Proposed Maximum       Proposed Maximum
  Title of Securities                                       Offering             Aggregate               Amount of
   to be Registered        Amount to be Registered     Price per Share(1)     Offering Price(1)     Registration Fee(2)
- -----------------------------------------------------------------------------------------------------------------------
                                                                                            
Common stock, par value        7,500,000 shares              $99.30             $744,750,000            $211,335.60
   $.02 per share
=======================================================================================================================


(1)  The Proposed Maximum Offering Price Per Share was estimated pursuant to
     Rules 457(c) and 457(h) promulgated under the Securities Act of 1933, as
     amended. Pursuant to Rule 457(h), in the case of an employee stock option
     plan, the aggregate offering price is to be computed upon the basis of the
     price at which the options may be exercised, or, if such price is not
     known, upon the basis of the average of the high and low reported prices
     pursuant to Rule 457(c). To be registered hereunder are 7,500,000 shares of
     the common stock, par value $.02 per share, of Genentech, Inc., which are
     referred to as the "Shares." Options covering 6,457,670 of the Shares have
     been granted under the 1999 Stock Plan and have an option exercise price of
     $97.00. Options covering 200,000 of the Shares have been granted under the
     1991 Employee Stock Plan, and the weighted average exercise price of such
     options is $51.11. The actual exercise price of each option was determined
     with reference to the grant date of that option. The exercise price for the
     options under the 1999 Stock Plan covering the remaining 842,330 Shares is
     not known, and in accordance with Rule 457(c) was calculated with reference
     to the high and low prices of July 26, 1999 reported on the New York Stock
     Exchange of $126.00 and $130.75, respectively, the average of which is
     $128.375. The Proposed Maximum Offering Price Per Share represents the
     weighted average exercise price of the options covering the Shares, which
     is $99.30.

(2)  Previously paid.

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PART II: INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3:  INCORPORATION OF DOCUMENTS BY REFERENCE

     In this Registration Statement, "Genentech," "we," "us" and "our" refer to
Genentech, Inc. The Securities and Exchange Commission, or SEC, allows us to
"incorporate by reference" the information we file with it, which means we can
disclose important information by referring to those documents. The information
included in the following documents is incorporated by reference and is
considered to be a part of this Registration Statement. The most recent
information that we file with the SEC automatically updates and supersedes more
dated information. We have previously filed the following documents with the SEC
and incorporate them by reference into this Registration Statement:

     (a)  Our annual report on Form 10-K for the year ended December 31, 1998;

     (b)  Our quarterly reports on Form 10-Q for the quarters ended March 31,
1999, June 30, 1999 and September 30, 1999;

     (c)  Our current report on Form 8-K dated June 28, 1999;

     (d)  Our current report on Form 8-K dated July 28, 1999; and

     (e)  The description under the heading "Description of Capital Stock"
relating to our common stock in the prospectus included in our Amendment No. 3
to the Registration Statement on Form S-3 (Registration No. 333-80601) filed
with the SEC on July 16, 1999, and the description under the heading
"Description of Capital Stock" relating to the common stock in the our final
prospectus filed with the SEC pursuant to Rule 424(b) under the Securities Act
of 1933, as amended, which is commonly known as the Securities Act, including
any amendment or report filed for the purpose of updating that description.

     We also incorporate by reference all documents subsequently filed by us
pursuant to Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of
1934, as amended, which is commonly known as the Exchange Act, until all of the
shares registered under this Registration Statement are sold.

     We will provide without charge to each person to whom a prospectus is
delivered, including any beneficial owner, a copy of any or all of the
information that has been incorporated by reference in this Registration
Statement. If you would like to obtain this information from us, please direct
your request to the Investor Relations Department, either in writing or by
telephone, to Genentech, Inc., 1 DNA Way, South San Francisco, California 94080,
Attention Investor Relations (650) 225-1260.


ITEM 4:  DESCRIPTION OF SECURITIES

     We have incorporated by reference the description under the heading
"Description of Capital Stock" relating to our common stock in the prospectus
included in our Amendment No. 3 to the Registration Statement on Form S-3
(Registration No. 333-80601) filed with the SEC on July 16, 1999, and the
description under the heading "Description of Capital Stock" relating to the
common stock in the our final prospectus filed with the SEC pursuant to Rule
424(b) under the Securities Act, including any amendment or report filed for the
purpose of updating that description.


ITEM 5:  INTERESTS OF NAMED EXPERTS AND COUNSEL

     Stephen G. Juelsgaard, Senior Vice President, General Counsel and Secretary
of Genentech, is an officer of Genentech and has received options under our 1999
Stock Plan and our 1991 Employee Stock Plan.

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ITEM 6:  INDEMNIFICATION OF DIRECTORS AND OFFICERS

     Our certificate of incorporation limits, to the fullest extent permitted by
Delaware corporate law, the personal liability of directors for monetary damages
for breach of their fiduciary duties.

     Section 145 of the General Corporation Law of the State of Delaware (the
"DGCL") provides, in summary, that directors and officers of Delaware
corporations are entitled, under certain circumstances, to be indemnified
against all expenses and liabilities (including attorneys' fees) incurred by
them as a result of suits brought against them in their capacity as a director
or officer, if they acted in good faith and in a manner they reasonably believed
to be in or not opposed to the best interests of the corporation, and with
respect to any criminal action or proceeding, if they had no reasonable cause to
believe their conduct was unlawful; provided, that no indemnification may be
made against expenses in respect of any claim, issue or matter as to which they
shall have been adjudged to be liable to the corporation, unless and only to the
extent that the court in which such action or suit was brought shall determine
upon application that, despite the adjudication of liability but in view of all
the circumstances of the case, they are fairly and reasonably entitled to
indemnity for such expenses which the court shall deem proper. Any such
indemnification may be made by the corporation only as authorized in each
specific case upon a determination by the stockholders or disinterested
directors that indemnification is proper because the indemnitee has met the
applicable standard of conduct.

     Our board of directors may provide similar indemnification to our officers,
employees and agents as it deems appropriate and as authorized by Delaware law.
We may purchase insurance on behalf of any director, officer, employee or agent
against any expense incurred by such person in his or her capacity.

     Our certificate of incorporation also provides that Roche and the officers
or directors of Roche Holdings, Inc., or Roche, which is our majority
stockholder, will not be presumed liable to us or our stockholders for breach of
any fiduciary duty or duty of loyalty, failure to act in the best interests of
Genentech, or receipt of any improper personal benefit, simply because Roche or
any director or officer of Roche, in good faith, takes any action, exercises any
right or gives or withholds any consent with respect to any agreement or
contract between Roche and Genentech.

     In addition, Roche will not be liable to us or our stockholders for breach
of any fiduciary duty if Roche pursues or acquires a potential corporate
opportunity of ours or does not inform us of a potential corporate opportunity.
If a director, officer or employee of Genentech who is also a director, officer
or employee of Roche knows of a potential transaction or matter that may be a
corporate opportunity both for Genentech and Roche, the director, officer or
employee is entitled to offer the corporate opportunity to us or Roche as the
director, officer or employee deems appropriate under the circumstances in his
or her sole discretion, and no such director, officer or employee will be liable
to us or our stockholders for breach of any fiduciary duty or duty of loyalty or
failure to act in our best interests or the derivation of any improper personal
benefit by reason of the fact that such director, officer or employee offered
such corporate opportunity to Roche (rather than to us) or did not communicate
information regarding such corporate opportunity to us, or Roche pursues or
acquires such corporate opportunity for itself or directs such corporate
opportunity to another person or does not communicate the corporate opportunity
to us.

     Neither Roche nor any officer or director thereof shall be liable to us or
our stockholders for breach of any fiduciary duty or duty of loyalty or failure
to act in (or not opposed to) our best interests or the derivation of any
improper personal benefit by reason of the fact that Roche or an officer of
director thereof in good faith takes any action or exercises any rights or gives
or withholds any consent in connection with any agreement or contract between
Roche and Genentech. No vote cast or other action taken by any person who is an
officer, director or other representative of Roche, which vote is cast or action
is taken by such person in his capacity as a director of Genentech, shall
constitute an action of or the exercise of a right by or a consent of Roche for
the purpose of any such agreement or contract.


ITEM 7:  EXEMPTION FROM REGISTRATION CLAIMED

     Not applicable.

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ITEM 8:  EXHIBITS



EXHIBIT
NUMBER
         
  5         Opinion of Stephen G. Juelsgaard, Esq.
 15.1       Letter re: Unaudited Interim Financial Information.(*)
 23.1       Consent of Ernst & Young LLP, independent auditors.(*)
 23.2       Consent of Stephen G. Juelsgaard, Esq. is contained in Exhibit 5 to
            this Registration Statement.
 24         Power of Attorney is contained on the signature pages.(**)
 99.1       1999 Stock Plan.(*)
 99.2       1991 Employee Stock Plan (as amended effective April 13, 1999).
- ------------------

(*)  Previously filed.

(**) Previously filed with respect to Arthur D. Levinson, Louis J. Lavigne, Jr.,
     John M. Whiting, Franz B. Humer and Jonathan K.C. Knowles.


ITEM 9:  UNDERTAKINGS

1.   The undersigned 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.
                Notwithstanding the foregoing, any increase or decrease in
                volume of securities offered (if the total dollar value of
                securities offered would not exceed that which was registered)
                and any deviation from the low or high end of the estimated
                maximum offering range may be reflected in the form of
                prospectus filed with the SEC pursuant to Rule 424(b) if, in the
                aggregate, the changes in volume and price represent no more
                than a 20% change in the maximum aggregate offering price set
                forth in the "Calculation of Registration Fee" table in the
                effective registration statement.

          (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 (a)(i) and (a)(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
          issuer pursuant to section 13 or section 15(d) of the Exchange Act
          that are incorporated by reference herein.


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     (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
          herein, 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 undersigned 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 reference in the Registration Statement shall be deemed to
     be a new registration statement relating to the securities offered herein,
     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 SEC 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.

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                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, as amended, the
undersigned 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
Post-Effective Amendment No. 1 to the Registration Statement to be signed on its
behalf by the undersigned, thereunto duly authorized, in the City of South San
Francisco, State of California, on November 2, 1999.


                                            GENENTECH, INC.


                                            By: /s/ CYNTHIA J. LADD
                                               ---------------------------------
                                            Name:  Cynthia J. Ladd
                                            Title: Vice President, Corporate Law
                                                   and Assistant Secretary

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                                POWER OF ATTORNEY

     KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Arthur D. Levinson and Cynthia J. Ladd,
and each or any one of them, his true and lawful attorney-in-fact and agent,
with full power of substitution and resubstitution, for him and in his name,
place and stead, in any and all capacities, to sign any and all amendments
(including post-effective amendments) to this Post-Effective Amendment No. 1 to
the Registration Statement, and to file the same, with all exhibits thereto, and
other documents in connection therewith, with the Securities and Exchange
Commission, granting unto said attorneys-in-fact and agents, and each of them,
full power and authority to do and perform each and every act and thing
requisite and necessary to be done in connection therewith, as fully to all
intents and purposes as he might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents, or any of them, or their
or his substitutes or substitute, may lawfully do or cause to be done by virtue
hereof.

     Pursuant to the requirements of the Securities Act of 1933, this
Post-Effective Amendment No. 1 to the Registration Statement has been signed by
the following persons in the capacities and on the dates indicated.




               SIGNATURE                                 TITLE                             DATE
                                                                                
                   *                     Principal Executive Officer and Director     November 2, 1999
- -------------------------------------
          Arthur D. Levinson

                   *                     Principal Financial Officer                  November 2, 1999
- -------------------------------------
         Louis J. Lavigne, Jr.

                   *                     Principal Accounting Officer                 November 2, 1999
- -------------------------------------
            John M. Whiting

                                         Director
- -------------------------------------
            Herbert W. Boyer

                   *                     Director                                     November 2, 1999
- -------------------------------------
             Franz B. Humer

                   *                     Director                                     November 2, 1999
- -------------------------------------
         Jonathan K.C. Knowles

                                         Director
- -------------------------------------
           Charles A. Sanders

           /s/ MARK RICHMOND             Director                                     November 2, 1999
- -------------------------------------
             Mark Richmond


*By: /s/ CYNTHIA J. LADD
- -------------------------------------
        Cynthia J. Ladd
        Attorney-in-fact


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                                  EXHIBIT INDEX



EXHIBIT
NUMBER
         
  5         Opinion of Stephen G. Juelsgaard, Esq.
 15.1       Letter re: Unaudited Interim Financial Information.(*)
 23.1       Consent of Ernst & Young LLP, independent auditors.(*)
 23.2       Consent of Stephen G. Juelsgaard, Esq. is contained in Exhibit 5 to
            this Registration Statement.
 24         Power of Attorney is contained on the signature pages.(**)
 99.1       1999 Stock Plan.(*)
 99.2       1991 Employee Stock Plan (as amended effective April 13, 1999).

- ------------------
(*)  Previously filed.

(**) Previously filed with respect to Arthur D. Levinson, Louis J. Lavigne, Jr.,
     John M. Whiting, Franz B. Humer and Jonathan K.C. Knowles.