**Exhibit
        12.1**
 **CERTIFICATION
        PURSUANT TO**
 **SECTION
        302(a) OF THE SARBANES-OXLEY ACT OF 2002**
  I,
        Geoffrey P. Kempler, certify that:
  1.
              I
                  have reviewed this annual report on Form 20-F of Prana Biotechnology
                  Limited;
  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
                  registrant as of, and for, the periods presented in this
                  report;
  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)) for the
                  registrant
                  and 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 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;
  (b)
        [Paragraph omitted pursuant to SEC Release Nos. 33-8238 and
        34-47986]
  (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
  (d)
        Disclosed in this report any change in the registrant’s internal control over
        financial reporting that occurred during the registrant’s most recent fiscal
        quarter (the registrant’s fourth fiscal quarter in the case of an annual report)
        that has materially affected, or is reasonably likely to materially affect,
        the
        registrant’s internal control over financial reporting; and
  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):
  (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
  (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.
  Date:
        December 21, 2005
   /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.