jul2704_424b4
PROSPECTUS SUPPLEMENT FILED PURSUANT TO RULE 424(B)(4)
   
TO PROSPECTUS DATED MARCH 28, 2001 REGISTRATION NO. 333-37072

GENENTECH, INC.

SHARES OF COMMON STOCK

     This prospectus supplement relates to the sale by certain selling shareholders of our common stock, par value $.02 per share, that was originally delivered in exchange for Liquid Yield Option Notes due 2015 issued by Roche Holdings, Inc.

     This prospectus supplement should be read in conjunction with the prospectus dated March 28, 2001, which is to be delivered with this prospectus supplement. All capitalized terms used but not defined in the prospectus supplement shall have the meanings given them in the prospectus.

     The table below sets forth information as of the date hereof concerning beneficial ownership of the common stock of the selling shareholders as listed below. All information concerning beneficial ownership has been furnished by the selling shareholders.

NAME NUMBER OF SHARES OF
COMMON STOCK
OWNED PRIOR TO
OFFERING
NUMBER OF
SHARES OFFERED
NUMBER OF SHARES OF
COMMON STOCK
OWNED AFTER THE
OFFERING
PERCENTAGE OF
COMMON STOCK
OUTSTANDING





Aviator Master Fund 34,612 34,612 0 * 


* Less than 1%

THE SECURITIES OFFERED HEREBY INVOLVE A HIGH DEGREE OF RISK. SEE
“RISK FACTORS” BEGINNING ON PAGE 3 OF THE PROSPECTUS.

THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE
SECURITIES AND EXCHANGE COMMISSION NOR HAS THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED
UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY
REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.


The date of this Prospectus Supplement is •, 2004.