# 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;
|-- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|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 10, 2006

| |  | /s/ William P. Hales
William P. HalesPresident and Chief Executive Officer
| |  | ----------------------------------------------------------------------------------------

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