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                                                                    EXHIBIT 31.1


                   PRINCIPAL EXECUTIVE OFFICER CERTIFICATION


I, Samuel L. Shanaman, certify that:

1.   I have reviewed this Quarterly Report on Form 10-Q of PolyMedica
     Corporation;

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 periods 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)   [Paragraph omitted in accordance with SEC transition
           instructions contained in SEC Release 34-47986]
      c)   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
      d)   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 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.


Dated: August 5, 2004


                               /s/ Samuel L. Shanaman
                               ------------------------
                               Samuel L. Shanaman
                               Chairman of the Board and Chief Executive Officer

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