# Exhibit 31.1

# Certification of
Principal Executive OfficerPursuant to Rule 13a-14(a)
ofSecurities Exchange
Act of 1934

I, William P. Hales, the principal
executive officer of Hemagen Diagnostics Inc, 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;
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|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):
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| | 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:  August 21, 2006 |  | BY: /s/William P. Hales
      
      William P. Hales
      President and Chief Executive Officer
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