Exhibit 31.2


                                 CERTIFICATIONS

      I, Marc Costantini, certify that:

1.    I have reviewed this quarterly report on Form 10-Q of John Hancock
      Financial Services, Inc.;
2.    Based on my knowledge, this quarterly 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 officers 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 quarterly 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 officers and I have disclosed, based on
      our most recent evaluation of internal controls over financial reporting,
      to the registrant's auditors and the audit committee of 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 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: May 10, 2005

By:   /S/  MARC COSTANTINI
      --------------------------
      Marc Costantini
      Senior Vice President and
         Chief Financial Officer