SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

                                   FORM 8-A/A

               FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES
                    PURSUANT TO SECTION 12(b) OR (g) OF THE
                        SECURITIES EXCHANGE ACT OF 1934


                               AZTAR CORPORATION
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             (Exact Name of Registrant as Specified in Its Charter)


              Delaware                                   86-0636534
------------------------------------------        -----------------------------
(State of Incorporation or Organization)               (I.R.S. Employer
                                                       Identification no.)

        2390 Camelback Road, Suite 400
              Phoenix, Arizona                                 85016
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   (Address of Principal Executive Offices)                 (Zip Code)


If this form relates to the                     If this form relates to the
registration of a class of securities           registration of a class of
pursuant to Section 12(b) of the                securities pursuant to Section
Exchange Act and is effective upon              12(g) of the Exchange Act and
filing pursuant to General Instruction          is effective upon filing
A.(c), please check the following box.          pursuant to General Instruction
[x]                                             A.(d), please check the
                                                following box. [ ]

Securities Act registration statement file number to which this form relates:
N/A

Securities to be registered pursuant to Section 12(b) of the Act:

       Title of Each Class                    Name of Each Exchange on Which
       to be so Registered                    Each Class is to be Registered
       -------------------                    ------------------------------

    Preferred Stock Purchase Rights               New York Stock Exchange

Securities to be registered pursuant to Section 12(g) of the Act:

              None                                None
      ----------------------             ------------------------
         (Title of Class)                    (Name of Exchange)





Item 1.  Description of Registrant's Securities to be Registered

         Item 1 of Form 8-A filed by Aztar Corporation (the "Company") on
December 15, 1999 relating to Preferred Stock Purchase Rights is hereby amended
to provide:

         On March 13, 2006, Aztar Corporation (the "Company") entered into an
Agreement and Plan of Merger (the "Merger Agreement"), by and among the Company,
Pinnacle Entertainment, Inc., a Delaware corporation ("Pinnacle"), and PNK
Development 1, Inc., a Delaware corporation and wholly owned subsidiary of
Pinnacle ("Merger Subsidiary"), pursuant to which Merger Subsidiary will merge
with and into the Company (the "Merger"), on the terms and subject to the
conditions in the Merger Agreement. In connection with the Merger Agreement and
the transactions contemplated thereby, the Board of Directors of the Company
authorized the amendment of the Rights Agreement, dated as of December 14, 1999
(the "Rights Agreement"), between the Company and ChaseMellon Shareholder
Services, L.L.C. ("ChaseMellon"), as Rights Agent.

         On March 14, 2006, the Company and Mellon Investor Services LLC (as
successor to ChaseMellon) executed Amendment No. 1 (the "Amendment") to the
Rights Agreement. Capitalized terms used below but not defined herein shall
have the meanings assigned thereto in the Rights Agreement. The Amendment
provides that (i) neither Pinnacle nor any of its subsidiaries shall be deemed
an Acquiring Person (x) by virtue of their acquisition, or their right to
acquire, beneficial ownership of Common Stock of the Company as a result of
their execution of the Merger Agreement, (y) the consummation of the Merger, or
(z) any other transaction contemplated by the Merger, and (ii) no Distribution
Date, Stock Acquisition Date, Section 11(a)(ii) Event, Section 13 Event, and no
Triggering Event shall be deemed to have occurred by reason of the execution of
the Merger Agreement or the announcement or consummation of the transactions
contemplated thereby pursuant to the terms of the Merger Agreement. The
Amendment also provides that the Rights Agreement and the Rights established
therein will terminate in all respects immediately prior to the Effective Time
(as defined in the Merger Agreement).

         The Rights Agreement is filed as Exhibit 1 to the Company's
Registration Statement on Form 8-A, filed with the Securities and Exchange
Commission (the "Commission") on December 15, 1999 and is incorporated herein
by reference. The Amendment is filed as Exhibit 4.2 to the Current Report on
Form 8-K filed by the Company with the Commission on March 16, 2006 and is
incorporated herein by reference. The foregoing description of the Rights
Agreement and the Amendment does not purport to be complete and is qualified in
its entirety by reference to such exhibit.

Item 2.  Exhibits

         Exhibit No.        Description
         -----------        -----------

         4.1                Rights Agreement, dated as of December 14, 1999,
                            between Aztar Corporation and ChaseMellon
                            Shareholder Services, L.L.C., as Rights Agent,
                            filed as Exhibit 1 to Aztar's Corporation's
                            Registration Statement on Form 8-A, filed on
                            December 15, 1999, and incorporated herein by
                            reference.

         4.2                Amendment No. 1, dated as of March 14, 2006, to the
                            Rights Agreement, between Aztar Corporation and
                            Mellon Investor Services LLC (as successor to
                            ChaseMellon Shareholder Services, L.L.C.), as
                            Rights Agent, filed as Exhibit 4.2 to Current
                            Report on Form 8-K, filed by Aztar Corporation on
                            March 16, 2006, and incorporated herein by
                            reference.





                                   SIGNATURE

         Pursuant to the requirements of Section 12 of the Securities Exchange
Act of 1934, the Registrant has duly caused this Registration Statement or
amendment thereto to be signed on its behalf by the undersigned, thereunto duly
authorized.


Dated:  March 16, 2006

                                      AZTAR CORPORATION


                                      By:  /s/ Nelson W. Armstrong, Jr.
                                           -----------------------------
                                           Name:  Nelson W. Armstrong, Jr.
                                           Title: Vice President,
                                                  Administration and Secretary




                                 EXHIBIT INDEX

         Exhibit No.        Description
         -----------        -----------

         4.1                Rights Agreement, dated as of December 14, 1999,
                            between Aztar Corporation and ChaseMellon
                            Shareholder Services, L.L.C., as Rights Agent,
                            filed as Exhibit 1 to Aztar's Corporation's
                            Registration Statement on Form 8-A, filed on
                            December 15, 1999, and incorporated herein by
                            reference.

         4.2                Amendment No. 1, dated as of March 14, 2006, to the
                            Rights Agreement, between Aztar Corporation and
                            Mellon Investor Services LLC (as successor to
                            ChaseMellon Shareholder Services, L.L.C.), as
                            Rights Agent, filed as Exhibit 4.2 to Current
                            Report on Form 8-K, filed by Aztar Corporation on
                            March 16, 2006, and incorporated herein by
                            reference.