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                                                                    Exhibit 31.1

             CERTIFICATION OF PRESIDENT AND CHIEF EXECUTIVE OFFICER

I, Gregory E. A. Morrison, certify that:

         1.       I have reviewed this report on Form 10-Q of Platinum
                  Underwriters Holdings, Ltd. (the "registrant");

         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 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 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 (the registrant's fourth fiscal
                        quarter in the case of an 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 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
                  (or persons performing the equivalent functions):

                  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: August 13, 2003               /s/ GREGORY E. A. MORRISON
                                  ----------------------------------------------
                                    By: Gregory E. A. Morrison
                                    President and Chief Executive Officer