Exhibit 99.1
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The  following  certification  is provided by the  undersigned  Chief  Executive
Officer  of  Wintrust  Financial  Corporation  on the  basis  of such  officer's
knowledge  and belief for the sole purpose of complying  with 18 U.S.C.  Section
1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

                                  CERTIFICATION


In connection  with the Annual  Report of Wintrust  Financial  Corporation  (the
"Company")  on Form 10-K for the year ended  December 31, 2002 as filed with the
Securities and Exchange Commission on March 27, 2003, (the "Report"),  I, Edward
J. Wehmer, President and Chief Executive Officer of the Company, hereby certify,
pursuant to 18 U.S.C.  Section 1350,  as adopted  pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002, that:

         (1) The Report fully complies with the requirements of Section 13(a) or
15(d) of the Securities Exchange Act of 1934, as amended; and

         (2) The  information  contained in the Report fairly  presents,  in all
material  respects,  the  financial  condition  and results of operations of the
Company.


/s/  EDWARD J. WEHMER
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Name:  Edward J. Wehmer
Title: President and Chief Executive Officer
Date:  March 27, 2003