Exhibit 31.1



CEO Certification

I, Andrew Baker, as Chief Executive Officer of the Company, certify that:

1.   I have reviewed this annual report on Form 10-K of Life Sciences  Research,
     Inc.:

2.   Based on my  knowledge,  this  annual  report  does not  contain any untrue
     statement of a material fact or omit to state a material fact  necessary to
     make the statements  made, in light of the  circumstances  under which such
     statements  were made, not misleading with respect to the period covered by
     this annual report,

3.   Based on my  knowledge,  the  financial  statements,  and  other  financial
     information included in this annual report,  fairly present in all material
     respects the financial  condition,  results of operations and cash flows of
     the registrant as of, and for, the periods presented in this annual report,

4.   The  registrant's  other  certifying  officer(s) and I are  responsible for
     establishing and maintaining disclosure controls and procedures (as defined
     in Exchange Act Rules  13a-15(e) and 15d-15(e)  for the  registrant  and we
     have:

     a.   Designed  such  disclosure  controls  and  procedures,  or caused such
          disclosure   controls  and   procedures  to  be  designed   under  our
          supervision,  to ensure  that  material  information  relating  to the
          registrant,  including its consolidated subsidiaries, is made known to
          us by others within those entities,  particularly during the period in
          which this annual report is being prepared;

     b.   Evaluated the  effectiveness of the registrant's  disclosure  controls
          and  procedures  and presented in this annual  report our  conclusions
          about the effectiveness of the disclosure controls and procedures,  as
          of the end of the period  covered by this annual  report based on such
          evaluation; and

     c.   Disclosed  in  this  annual  report  any  change  in the  registrant's
          internal  control over financial  reporting  that occurred  during the
          registrant's  most recent  fiscal  quarter  (the  registrant's  fourth
          fiscal  quarter in the case of this annual report) that has materially
          affected,   or  is  reasonably  likely  to  materially   affect,   the
          registrant's internal control over financial reporting; and

5.   The registrant's other certifying officer(s) and I have disclosed, based on
     our most recent evaluation of internal control over financial reporting, to
     the registrant's  auditors and the audit committee of registrant's board of
     directors (or persons performing the equivalent function):

     a)   all significant  deficiencies and material weaknesses in the design or
          operation of internal  controls  over  financial  reporting  which are
          reasonably  likely to  adversely  affect the  registrant's  ability to
          record, process, summarize and report financial information; and

     b)   any fraud, whether or not material,  that involves management or other
          employees who have a  significant  role in the  registrant's  internal
          controls over financial reporting.



Date:    April 14, 2004                     /s/  Andrew H. Baker
                                                -------------------------
                                                 Andrew H. Baker
                                                 Chief Executive Officer