Exhibit 5.1

                                 April 21, 2006

SECURITIES AND EXCHANGE COMMISSION
100 F Street, N.E.
Washington, D.C. 20549

     RE: PRINCETON NATIONAL BANCORP, INC. -- REGISTRATION OF 26,158 SHARES OF
         COMMON STOCK, PAR VALUE $5.00 PER SHARE, ON FORM S-8 IN CONNECTION WITH
         CITIZENS FIRST NATIONAL BANK 401(K) & PROFIT SHARING PLAN

Ladies and Gentlemen:

     We have acted as counsel to Princeton National Bancorp, Inc., a Delaware
corporation (the "Company"), in connection with the Company's filing of a
Registration Statement on Form S-8 (the "Registration Statement") covering
26,158 shares of Common Stock, $5.00 par value per share (including an equal
number of Rights to purchase shares of Registrant's Series A Junior
Participating Preferred Stock) (together, the "Common Stock"), to be issued
pursuant to the Citizens First National Bank 401(k) & Profit Sharing Plan, as
amended (the "Plan").

     In this connection, we have made such investigation and have examined such
documents as we have deemed necessary in order to enable us to render the
opinion contained herein.

     Based upon the foregoing, it is our opinion that those shares of Common
Stock covered by the Registration Statement that are originally issued in
accordance with the terms of the Plan and as contemplated in the Registration
Statement and the Prospectus relating thereto, will, when so issued, be validly
issued, fully paid and nonassessable.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement.

                                        VERY TRULY YOURS,


                                        /s/ HOWARD & HOWARD ATTORNEYS, P.C.


                                        HOWARD & HOWARD ATTORNEYS, P.C.