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                                                                    EXHIBIT 31.1

                                 CERTIFICATIONS

I, Henry J. Fuchs, M.D. certify that:

1. I have reviewed this quarterly report on Form 10-Q of IntraBiotics
   Pharmaceuticals, 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
   registrant as of, and for, the periods presented in this report;

4. The registrant'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 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)  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 evaluations; and

   (c) 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(s) 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 registrant's board of
   directors (or persons performing the equivalent functions):

   a)  All significant deficiencies and material weaknesses in the design or
       operation of internal controls 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: August 13, 2003                       /s/ Henry J. Fuchs
                                            -----------------------
                                            Henry J. Fuchs, M.D.
                                            Chief Executive Officer