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Exhibit 12.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER
Pursuant to Rule 13a-14(a) and 15d-14(a)
Under the Securities Exchange Act of 1934, as Amended

I, Geoffrey P. Kempler, certify
that:

|1. | I
have reviewed this annual report on Form 20-F of Prana Biotechnology Limited;
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|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;
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|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;
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|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)) and internal
control over financial                     reporting (as defined in Exchange Act Rules
13a-15(f) and 15d-15(f)) for the                     registrant 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 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;
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| | (b)
                    Designed such internal control over financial reporting, or caused
such           internal control over financial reporting to be designed under our
supervision,           to provide reasonable assurance regarding the reliability of
financial reporting           and the preparation of financial statements for external
purposes in accordance           with generally accepted accounting principles;
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| | (c)
                    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
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| | (d) Disclosed in this report
any change in the registrant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
registrants internal control over financial reporting; and
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|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 the registrants                     board of directors (or persons performing
the equivalent function):
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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 registrant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 registrants internal control
over           financial reporting.
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Date: September 25, 2008

/s/ Geoffrey P. Kempler*Geoffrey P. Kempler
Chief Executive Officer

*     The
originally executed copy of this Certification will be maintained at the Registrants
offices and will be made available for inspection upon request.



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