**Exhibit
      31.1**





**Certification
      of Principal Executive Officer**


**Pursuant
      to Rule 13a-14(a) of**


**Securities
      Exchange Act of 1934**








I,
      William P. Hales, certify that:




1.  I
        have
        reviewed this quarterly report on Form 10-QSB 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 small business issuer as of, and
      for, the periods presented in this report;





4.  The
      small
      business issuer’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 small business issuer 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 small business issuer, 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 small business issuer'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 small business issuer’s internal control over
      financial reporting that occurred during the small business issuer’s most recent
      fiscal quarter that has materially affected, or is reasonably likely to
      materially affect, the small business issuer’s internal control over financial
      reporting; and





5.  The
      small
      business issuer’s other certifying officer and I have disclosed, based on our
      most recent evaluation of internal control over financial reporting, to the
      small business issuer’s auditors and the audit committee of the small business
      issuer’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 small business issuer’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 small business issuer’s internal control over
      financial reporting.





Date:  
      May 29, 2007


/s/
      William P. Hales


William
      P. Hales


President
      and Chief Executive Officer