<PAGE>
                                                                    EXHIBIT 21.1

                  SUBSIDIARIES OF LEXICON GENETICS INCORPORATED

     The subsidiaries of Lexicon Genetics Incorporated set forth below each do
business under the name stated.

<TABLE>
<CAPTION>
                                             State of Incorporation or
            Name of Subsidiary                       Formation
------------------------------------------   -------------------------
<S>                                          <C>
Lexicon Pharmaceuticals (New Jersey), Inc.            Delaware
Lex-Gen Woodlands GP, LLC                             Delaware
Lex-Gen (Delaware), LLC                               Delaware
Lex-Gen Woodlands, L.P.                               Delaware
</TABLE>
