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  Annual  Report of Life  Sciences  Research,  Inc.
("LSR") on Form 10-K for the period ended  December 31, 2003,  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; and

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



Date:    April 14, 2004                    /s/     Andrew H. Baker
                                                   ---------------------
                                                   Andrew H. Baker
                                                   Chairman of the Board
                                                   and Chief Executive Officer