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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


Date: December 23, 2004                     /s/ William P. Hales
                                           ------------------------------
                                           William P. Hales
                                           President and Chief Executive Officer