Exhibit 99.1


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 Quarterly Report of Wintrust  Financial  Corporation (the
"Company")  on Form 10-Q for the period  ended  June 30,  2002 as filed with the
Securities and Exchange Commission on August 14, 2002, (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
                                   ---------------------------------------------
                                   Name:  Edward J. Wehmer
                                   Title:  President and Chief Executive Officer
                                   Date:  August 14, 2002