8-K

                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

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

                                    FORM 8-K

                                 CURRENT REPORT


                     Pursuant to Section 13 or 15(d) of the

                         Securities Exchange Act of 1934


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


         Date of Report (Date of earliest event reported): July 21, 2000


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


    DELAWARE                    0-28218                         77-0319159
- ------------------       ------------------------          --------------------
(State of                (Commission File Number)            (IRS Employer
incorporation)                                             Identification No.)



        3380 Central Expressway, Santa Clara, California         95051
- -------------------------------------------------------------------------------
           (Address of principal executive offices)            (Zip Code)


                                 (408) 731-5000
                         -------------------------------
                         (Registrant's telephone number,
                              including area code)


                                       N/A
- -------------------------------------------------------------------------------
          (Former name or former address, if changed since last report)








Item 5.   OTHER EVENTS.

         On July 21, 2000, the Company announced that its Board of Directors
had approved a two-for-one stock split of the Company's outstanding shares of
Common Stock to be effected in the form of a 100% stock dividend. The
dividend will be distributed on August 21, 2000 to Company stockholders of
record as of the close of business on August 10, 2000. The Company's press
release announcing this stock split is filed as Exhibit 99.1 hereto and is
incorporated by reference herein.

Item 7.   FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS.

(c)  Exhibits

The following exhibit is filed herewith:

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


99.1                       Press Release



                           SIGNATURE



     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                    AFFYMETRIX, INC.



                                    By:  /s/ VERN NORVIEL
                                       -------------------------------------
                                       Name:  Vern Norviel
                                       Title: Senior Vice President, General
                                              Counsel and Secretary



Date: July 21, 2000






                                  EXHIBIT INDEX



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

99.1              Press Release

EX-99.1

                                                                   EXHIBIT 99.1

FOR IMMEDIATE RELEASE
- ---------------------

Contact:  Affymetrix, Inc.
          ----------------
          Edward M. Hurwitz                      Anne Bowdidge
          Vice President and                     Director of Investor Relations
          Chief Financial Officer                (408) 731-5925
          (408) 731-5000


                   AFFYMETRIX ANNOUNCES TWO-FOR-ONE STOCK SPLIT

SANTA CLARA, CA - July 21, 2000 -- Affymetrix, Inc., (NASDAQ: AFFX) announced
today that its Board of Directors has approved a two-for-one stock split of
the Company's outstanding shares of common stock.

The stock split entitles each stockholder of record at the close of business
on August 10, 2000, to receive a stock dividend of one additional share for
every share of Affymetrix Common Stock held on that date. The additional
shares resulting from the stock split will be distributed by the Company's
transfer agent on August 21, 2000.

The Company currently has approximately 27.6 million shares outstanding. Upon
completion of the split, the number will increase to approximately 55.2
million.

Affymetrix is a leader in developing and commercializing systems to acquire,
analyze and manage complex genetic information in order to improve the
quality of life. The Company's GeneChip(R) system consists of disposable DNA
probe arrays containing gene sequences on a chip, reagents for use with the
probe arrays, a scanner, and other instruments to process the probe arrays
and software to analyze and manage genetic information. The Company's spotted
array system enables individual researchers to create and analyze custom
microarrays on an easy-to-use, cost efficient platform. Additional
information on Affymetrix and GeneChip technology can be found at
www.affymetrix.com.

All statements in this press release that are not historical are
forward-looking statements within the meaning of Section 21E of the
Securities Exchange Act as amended, including statements regarding
Affymetrix' "expectations," "beliefs," "hopes," "intentions," "strategies" or
the like. Such statements are subject to risks and uncertainties that could
cause actual results to differ materially for Affymetrix from those
projected, including, but not limited to, uncertainties relating to
technological approaches, product development, manufacturing, market
acceptance, uncertainties related to cost and pricing of Affymetrix products,
dependence on collaborative partners, uncertainties relating to sole source
suppliers, uncertainties relating to FDA and other regulatory approvals,
competition, risks relating to intellectual property of others and the
uncertainties of patent protection and litigation. These and other risk
factors are discussed in Affymetrix' Form 10-K for the year ended December
31, 1999 and Affymetrix' other SEC reports, including its Quarterly Reports
on Form 10-Q for subsequent quarterly periods. Affymetrix expressly disclaims
any obligation or undertaking to release publicly any updates or revisions to
any forward-looking statements contained herein to reflect any change in
Affymetrix' expectations with regard thereto or any change in events,
conditions, or circumstances on which any such statements are based.
Affymetrix, GeneChip and the Affymetrix logo are registered trademarks used
by Affymetrix, Inc.