<PAGE>

                                                                    Exhibit 31.2

                                 CERTIFICATIONS

             CERTIFICATION OF CHIEF FINANCIAL OFFICER AND TREASURER

I, D. J. Paul E. Cowan, certify that:

1.       I HAVE REVIEWED THIS QUARTERLY REPORT OF INVERESK RESEARCH GROUP, INC.;

2.       BASED ON MY KNOWLEDGE, THIS 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 REPORT;

3.       BASED ON MY KNOWLEDGE, THE FINANCIAL STATEMENTS, AND OTHER FINANCIAL
         INFORMATION INCLUDED IN THIS 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 REPORT;

4.       THE REGISTRANT'S OTHER CERTIFYING OFFICER 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 HAVE:

         a)       Designed such disclosure controls and procedures, or caused
         such 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 report is
         being prepared;

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

         c)       Disclosed in this report any change in the registrant's
         internal control over financial reporting that occurred during the
         registrant's most recent fiscal quarter 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 OFFICERS 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 THE
         REGISTRANT'S BOARD OF DIRECTORS:

         a)       All significant deficiencies and material weaknesses in the
         design or operation of internal control 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 control over financial reporting.

Date:  November 7, 2003                                /S/ D. J. Paul E. Cowan
                                                       -----------------------
                                                       Chief Financial Officer
                                                       and Treasurer

                                       40