EXHIBIT 99.A

# CERTIFICATIONS PURSUANT TO SECTION 302 OF
THE SARBANES-OXLEY ACT OF 2002

I, Brad Thompson, certify
that:

|1. |  | I
have reviewed this annual report on Form 40-F of Oncolytics           Biotech Inc.;
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|2. |  | Based
on my knowledge, this annual 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 annual report;
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|3. |  | Based
on my knowledge, the financial statements, and other financial           information
included in this annual report, fairly present in all material           respects the
financial condition, results of operations and cash flows of the           issuer as of,
and for, the periods presented in this annual report;
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|4. |  | The
issuers other certifying officer(s) 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 issuer and have:
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| | 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 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;
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| | b) |  | Evaluated
the effectiveness of the 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
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| | c) |  | Disclosed
in this report any change in the issuers internal control over financial reporting
that occurred during the period covered by the annual report that has materially
affected, or is reasonably likely to materially affect, the issuers internal
control over financial reporting; and
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|5. |  | The
issuers other certifying officer(s) and I have disclosed, based           on our
most recent evaluation of internal control over financial reporting, to           the
issuers auditors and the audit committee of the 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 issuers
ability to record, process, summarize and report financial information; and
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| | b) |  | Any
fraud, whether or not material, that involves management or other employees who have a
significant role in the issuers internal control over financial reporting.
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|March 4, 2005 | By:  
/s/ Brad Thompson         Brad Thompson
         President & Chief Executive Officer
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