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                                  EXHIBIT 31.1

                  CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER
                          PURSUANT TO RULE 13A-14(a) OF
                         SECURITIES EXCHANGE ACT OF 1934


I, William P. Hales, the principal executive officer of Hemagen Diagnostics,
Inc. certify that:

1.   I have reviewed this annual report on Form 10-KSB of Hemagen Diagnostics,
     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 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 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 year 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 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; and

6.   The registrant's other certifying officers and I have indicated in this
     annual report whether or not there were significant changes in internal
     controls or in other factors that could significantly affect internal
     controls subsequent to the date of our most recent evaluation, including
     any corrective actions with regard to significant deficiencies and material
     weaknesses.



Date: December 22, 2003                    /s/ William P. Hales
                                           -------------------------------------
                                           William P. Hales
                                           President and Chief Executive Officer