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Exhibit 31.1

CERTIFICATION

I, Jonah Shacknai, certify that:



| | 1. |  | I have reviewed this annual report on Form 10-K of Medicis
Pharmaceutical Corporation;                                                                                                                                                                                                                    
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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 annual 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(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:                                                                            
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| | (a) |  | Designed such 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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| | (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 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
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| | 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 the registrant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 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.                                                                                               

Date: September 29, 2003

JONAH SHACKNAI

/s/ JONAH SHACKNAI
(Jonah Shacknai)
Chairman of the Board and
Chief Executive Officer