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                                  UNITED STATES
                       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 31, 2003

                          LEXICON GENETICS INCORPORATED
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

           DELAWARE                   000-30111                 76-0474169
(STATE OR OTHER JURISDICTION OF (COMMISSION FILE NUMBER)     (I.R.S. EMPLOYER
INCORPORATION OR ORGANIZATION)                            IDENTIFICATION NUMBER)

                          8800 TECHNOLOGY FOREST PLACE
                           THE WOODLANDS, TEXAS 77381
                         (ADDRESS OF PRINCIPAL EXECUTIVE
                              OFFICES AND ZIP CODE)

                                 (281) 863-3000
                         (REGISTRANT'S TELEPHONE NUMBER,
                              INCLUDING AREA CODE)

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ITEM 7. FINANCIAL STATEMENTS AND EXHIBITS

         (c) Exhibits

EXHIBIT NO.                       DESCRIPTION
-----------      -----------------------------------------------------
      99.1    -- Press Release of Lexicon Genetics Incorporated dated
                 July 31, 2003

ITEM 12. RESULTS OF OPERATIONS AND FINANCIAL CONDITION

         On July 31, 2003, we issued a press release to report our financial
results for the quarter ended June 30, 2003. A copy of the press release is
attached to this current report on Form 8-K as Exhibit 99.1.

         The information in this Form 8-K and the Exhibit attached to this
Form 8-K shall not be deemed "filed" for purposes of Section 18 of the
Securities Exchange Act of 1934 (the "Exchange Act") or otherwise subject to the
liabilities of that section, nor shall it be deemed incorporated by reference in
any filing under the Securities Act of 1933 or the Exchange Act, except as
expressly set forth by specific reference in such a filing.

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                                   SIGNATURES

         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 thereunto duly authorized.

                                           LEXICON GENETICS INCORPORATED

Date: July 31, 2003                        By: /s/ JEFFREY L. WADE
                                               -------------------------------
                                               Jeffrey L. Wade
                                               Executive Vice President and
                                               General Counsel

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                                INDEX TO EXHIBITS



EXHIBIT NO.                       DESCRIPTION
-----------       ----------------------------------------------------
               
      99.1     -- Press Release of Lexicon Genetics Incorporated dated
                  July 31, 2003