As filed with the Securities and Exchange Commission on February 16, 2006



                                             Securities Act File No. 333-126305
                                      Investment Company Act File No. 811-06567
================================================================================


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM N-14
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933



                          PRE-EFFECTIVE AMENDMENT NO.
                       [X] POST-EFFECTIVE AMENDMENT NO. 1



                        (CHECK APPROPRIATE BOX OR BOXES)

                     VAN KAMPEN MUNICIPAL OPPORTUNITY TRUST

        (EXACT NAME OF REGISTRANT AS SPECIFIED IN DECLARATION OF TRUST)

                                 (800) 341-2929
                        (AREA CODE AND TELEPHONE NUMBER)

                           1221 AVENUE OF THE AMERICAS
                            NEW YORK, NEW YORK 10020
                    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)

                              AMY R. DOBERMAN, ESQ.
                                MANAGING DIRECTOR
                           VAN KAMPEN INVESTMENTS INC.
                           1221 AVENUE OF THE AMERICAS
                            NEW YORK, NEW YORK 10020
                     (NAME AND ADDRESS OF AGENT FOR SERVICE)

                                   COPIES TO:

                             CHARLES B. TAYLOR, ESQ.
                    SKADDEN, ARPS, SLATE, MEAGHER & FLOM LLP
                              333 WEST WACKER DRIVE
                             CHICAGO, ILLINOIS 60606
                                 (312) 407-0700


================================================================================









                                EXPLANATORY NOTE


         The Joint Proxy Statement/Prospectus and the Statement of Additional
Information in the form filed on September 7, 2005 pursuant to Rule 497 of the
General Rules and Regulations under the Securities Act of 1933, as amended, are
incorporated herein by reference.



         This amendment is being filed in order to file, as Exhibit 12 to this
Registration Statement, the tax opinion of Skadden, Arps, Slate, Meagher & Flom
LLP, tax counsel for the Registrant, and to file, as Exhibit 16 to this
Registration Statement, a power of attorney executed by certain officers of the
Registrant and each of the current members of the Registrant's Board of
Trustees.





                           PART C: OTHER INFORMATION

ITEM 15. INDEMNIFICATION


         There has been no change in the information set forth in Item 15 of the
most recently filed Registration Statement of Van Kampen Municipal Opportunity
Trust (the "Registrant") on Form N-14 under the Securities Act of 1933 and the
Investment Company Act of 1940 (File Nos. 333-126305 and 811-06567) as filed
with the Securities and Exchange Commission on August 10, 2005, which
information is incorporated herein by reference.





ITEM 16. EXHIBITS



         (1)   (a)   Declaration of Trust of the Registrant and
                     amendments thereto++



               (b)   Form of Certificate of Vote Establishing Preferred Shares
                     and amendments thereto (included as Appendix B to the
                     Statement of Additional Information contained in this
                     Registration Statement)++



         (2)   (a)   Bylaws of the Registrant++



               (b)   Articles of Amendment to the Bylaws++


         (3)         Not Applicable


         (4)         Form of Agreement and Plan of Reorganization between the
                     Registrant and the Target Fund (included as Appendix A to
                     the Statement of Additional Information contained in this
                     Registration Statement)++



         (5)   (a)   Specimen share certificate for common shares of the
                     Registrant++



               (b)   Specimen share certificate for preferred shares of the
                     Registrant++



         (6)   (a)   Investment Advisory Agreement++



               (b)   Amendment Number One to the Investment Advisory
                     Agreement++


         (7)         Not Applicable


         (8)   (a)   Form of Amended and Restated Deferred Compensation Plan++



               (b)   Form of Retirement Plan++



         (9)   (a)   Custodian Contract++



               (b)   Amendment to Custodian Contract++


         (10)        Not Applicable


         (11)        Opinion and Consent of Skadden, Arps, Slate, Meagher & Flom
                     LLP++



         (12)        Tax opinion of Skadden, Arps, Slate, Meagher & Flom LLP+



         (13)  (a)   Transfer Agency and Service Agreement++



               (b)   Auction Agency Agreement++



               (c)   Form of Broker-Dealer Agreement++



               (d)   (i)   Letter of Representations++



                     (ii)  Form of Letter of Representations ++



               (e)   Fund Accounting Agreement++



               (f)   Amended and Restated Legal Services Agreement++



         (14)        Consent of Independent Registered Public Accounting
                     Firm++


         (15)        Not Applicable


         (16)        Power of Attorney+






         (17)  (a)   Code of Ethics of the Investment Adviser++



               (b)   Code of Ethics of the Funds++



         (99)  (a)   Proxy card for the Target Fund++



               (b)   Proxy card for the Registrant++





         +     Filed herewith.





         ++       Incorporated by reference to Pre-Effective Amendment No. 1 to
                  Registrant's Registration Statement on Form N-14, File Nos.
                  333-126305 and 811-06567, filed August 10,2005.



ITEM 17. UNDERTAKINGS

         (1)      The undersigned Registrant agrees that prior to any public
                  reoffering of the securities registered through use of a
                  prospectus which is part of this Registration Statement by any
                  person or party who is deemed to be an underwriter within the
                  meaning of Rule 145(c) of the Securities Act of 1933, as
                  amended, the reoffering prospectus will contain information
                  called for by the applicable registration form for reofferings
                  by persons who may be deemed underwriters, in addition to the
                  information called for by other items of the applicable form.

         (2)      The undersigned Registrant agrees that every prospectus that
                  is filed under paragraph (1) above will be filed as part of an
                  amendment to the registration statement and will not be used
                  until the amendment is effective, and that, in determining any
                  liability under the Securities Act of 1933, as amended, each
                  post-effective amendment shall be deemed to be a new
                  registration statement for the securities offered therein, and
                  the offering of securities at that time shall be deemed to be
                  the initial bona fide offering of them.





                                      C-1


                                   SIGNATURES


         Pursuant to the requirements of the Securities Act of 1933, as amended,
the Registrant has duly caused this Amendment to the Registration Statement to
be signed on its behalf by the undersigned, hereunto duly authorized, in the
City of New York, and the Sate of New York, on February 16, 2006.


                                        VAN KAMPEN MUNICIPAL OPPORTUNITY TRUST

                                        By:   /s/ Stefanie V. Chang Yu
                                              ----------------------------------
                                               Stefanie V. Chang Yu
                                               Vice President and Secretary


         Pursuant to the requirements of the Securities Act of 1933, as amended,
this Amendment to the Registration Statement has been signed below by the
following persons in the capacities and on the date indicated.


               SIGNATURES             TITLE
               ----------             -----
PRINCIPAL EXECUTIVE OFFICER:


/s/ Ronald E. Robison*                President and Principal Executive Officer
--------------------------------
Ronald E. Robison


PRINCIPAL FINANCIAL OFFICER:


/s/ Phillip G. Goff                   Chief Financial Officer and Treasurer
--------------------------------
Phillip G. Goff


TRUSTEES:

/s/ David C. Arch*                    Trustee
--------------------------------
David C. Arch

/s/ Jerry D. Choate*                  Trustee
--------------------------------
Jerry D. Choate

/s/ Rod Dammeyer*                     Trustee
--------------------------------
Rod Dammeyer


                                      C-2



/s/ Linda Hutton Heagy*                 Trustee
---------------------------------------
Linda Hutton Heagy

/s/ R. Craig Kennedy*                   Trustee
---------------------------------------
R. Craig Kennedy

/s/ Howard J Kerr*                      Trustee
---------------------------------------
Howard J Kerr




/s/ Jack E. Nelson*                     Trustee
---------------------------------------
Jack E. Nelson




/s/ Hugo F. Sonnenschein*               Trustee
---------------------------------------
Hugo F. Sonnenschein

/s/ Wayne W. Whalen*                     Trustee
---------------------------------------
Wayne W. Whalen

/s/ Suzanne H. Woolsey*                  Trustee
---------------------------------------
Suzanne H. Woolsey

------------------
* Signed by Stefanie V. Chang Yu pursuant to a power of attorney filed herewith.


         /s/ Stefanie V. Chang Yu                   February 16, 2006
         ----------------------------------------
         Stefanie V. Chang Yu
         Attorney-in-Fact




                                      C-3

                                  EXHIBIT INDEX


(12)     Tax opinion of Skadden, Arps, Slate, Meagher & Flom LLP



(16)     Power of Attorney