As filed with the Securities and Exchange Commission on September 4, 2003.
                                                      Registration No. 333-92075
================================================================================

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                 ---------------

                   POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-3
                             REGISTRATION STATEMENT

                        UNDER THE SECURITIES ACT OF 1933

                                 ---------------

                         WINTRUST FINANCIAL CORPORATION
             (Exact Name of Registrant as Specified in its Charter)

               ILLINOIS                                         36-3873352
     (State or Other Jurisdiction                             (IRS Employer
  of Incorporation or Organization)                       Identification Number)

                              727 NORTH BANK LANE
                        LAKE FOREST, ILLINOIS 60045-1951
                                 (847) 615-4096
               (Address, Including Zip Code, and Telephone Number,
        Including Area Code, of Registrant's Principal Executive Offices)

                                DAVID A. DYKSTRA
            SENIOR EXECUTIVE VICE PRESIDENT AND CHIEF OPERATING OFFICER
                               727 NORTH BANK LANE
                        LAKE FOREST, ILLINOIS 60045-1951
                                 (847) 615-4096
            (Name, Address, Including Zip Code, and Telephone Number,
                   Including Area Code, of Agent for Service)

      The Commission is requested to send copies of all communications to:

                             JENNIFER R. EVANS, ESQ.
                           JENNIFER DURHAM KING, ESQ.
                     VEDDER, PRICE, KAUFMAN & KAMMHOLZ, P.C.
                            222 NORTH LASALLE STREET
                          CHICAGO, ILLINOIS 60601-1003
                                 (312) 609-7500

                                 ---------------

         Approximate date of commencement of proposed sale to the public: Not
applicable.

         If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, check the following box.
[ ]

         If any of the securities being registered on this Form are to be
offered on a delayed or continuous basis pursuant to Rule 415 under the
Securities Act of 1933, other than securities offered only in connection with
dividend or interest reinvestment plans, check the following box. [ ]

         If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, check the following box and
list the Securities Act registration statement number of the earlier effective
registration statement for the same offering. [ ]

         If this Form is a post-effective amendment filed pursuant to Rule
462(c) under the Securities Act, check the following box and list the Securities
Act registration statement number of the earlier effective registration
statement for the same offering. [ ]

         If delivery of the prospectus is expected to be made pursuant to Rule
434, please check the following box. [ ]





                                EXPLANATORY NOTE

DEREGISTRATION OF SECURITIES

         On December 3, 1999, Wintrust Financial Corporation, an Illinois
corporation, filed with the Securities and Exchange Commission (the
"Commission") a Registration Statement on Form S-3 (File No. 333-92075) (the
"Registration Statement") pursuant to Rule 415 of the Securities Act of 1933, as
amended, registering a total of 529,413 shares (adjusted to reflect the 3-for-2
stock split effective March 14, 2002) of its common stock, without par value,
for the offer and sale from time to time by the selling shareholders named in
the Registration Statement. The Commission declared the Registration Statement
effective on December 16, 1999. The selling shareholders purchased these shares
directly from us in a private placement transaction in November 1999, and the
shares can now be resold under Rule 144(k) without registration.

         In accordance with the undertakings contained in the Registration
Statement, we are filing this post-effective amendment to remove from
registration any shares not yet resold by the selling shareholders. Accordingly,
upon effectiveness of this Post-Effective Amendment No. 1 to the Registration
Statement, all the shares of our common stock formerly covered by the
Registration Statement that remain available for sale by the selling
shareholders will be deregistered.





                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, as amended,
the registrant has duly caused this Post-Effective Amendment No. 1 to the
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Lake Forest, State of Illinois, on this 3rd day
of September, 2003.

                                WINTRUST FINANCIAL CORPORATION

                                By:  /s/ David A. Dykstra
                                   ---------------------------------------------
                                   David A. Dykstra
                                   Senior Executive Vice President and
                                   Chief Operating Officer

         Pursuant to the requirements of the Securities Act of 1933, as amended,
this Post-Effective Amendment No. 1 to the Registration Statement has been
signed by the following persons on the 3rd day of September, 2003 in the
capacities indicated.

           SIGNATURE                                  TITLE
           ---------                                  -----

/s/  Edward J. Wehmer                        President, Chief Executive
---------------------------------                 Officer and Director
     Edward J. Wehmer

/s/  David L. Stoehr                         Executive Vice Presiden and
---------------------------------             Chief Financial Officer
     David L. Stoehr                       (Principal Accounting Officer)

/s/  John S. Lillard*
---------------------------------             Chairman and Director
     John S. Lillard

/s/  Peter D. Crist*
---------------------------------                    Director
     Peter D. Crist

/s/ Bruce K. Crowther*
---------------------------------                    Director
     Bruce K. Crowther


---------------------------------                    Director
     Bert A. Getz, Jr.


---------------------------------                    Director
     Philip W. Hummer


---------------------------------                    Director
     James B. McCarthy

/s/  Marguerite Savard McKenna*
---------------------------------                    Director
     Marguerite Savard McKenna


---------------------------------                    Director
     Albin F. Moschner


---------------------------------                    Director
     Thomas J. Neis





           SIGNATURE                                  TITLE
           ---------                                  -----


---------------------------------                    Director
     Hollis W. Rademacher

/s/  J. Christopher Reyes*
---------------------------------                    Director
     J. Christopher Reyes

/s/  John J. Schornack*
---------------------------------                    Director
     John J. Schornack

/s/  Ingrid S. Stafford*
---------------------------------                    Director
     Ingrid S. Stafford


----------
*Signed pursuant to power of attorney


By: /s/ David A. Dykstra
    ---------------------------------
         David A. Dykstra
         Attorney-in-fact