LIFE SCIENCES RESEARCH, INC. AND SUBSIDIARIES


                                                                   Exhibit 32.1


                            CERTIFICATION PURSUANT TO
                 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Life Sciences Research, Inc. (LSR) on
Form 10-Q for the period ended March 31, 2004, as filed with the  Securities and
Exchange  Commission  on the date  hereof  (the  "Report"),  I, Andrew H. Baker,
Chairman of the Board and Chief Executive Officer of LSR,  certify,  pursuant to
18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley
Act of 2002, that:

     (1)  The Report fully  complies with the  requirements  of Section 13(a) or
          15(d) of the Securities Exchange Act of 1934, as amended and

     (2)  The  Information  contained  in the  report  fairly  presents,  in all
          material respects,  the financial  condition and results of operations
          of LSR.

Date:    May 6, 2004

                                          /s/ Andrew Baker
                                          ------------------------------

                                          Andrew H. Baker
                                          Chairman of the Board
                                          and Chief Executive Officer
                                          (Principal Executive Officer)