UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT

                Pursuant to Section 13 OR 15(d) of the Securities
                              Exchange Act of 1934

              Date of Report (Date of the earliest event reported)
                                  May 24, 2006
                                ----------------

                             Kronos Worldwide, Inc.
             ------------------------------------------------------
             (Exact name of Registrant as specified in its charter)

     Delaware                       1-31763                   76-0294959
-------------------            ------------------          -----------------
 (State or other                 (Commission                 (IRS Employer
 jurisdiction of                  File Number)               Identification
  incorporation)                                                   No.)

             5430 LBJ Freeway, Suite 1700, Dallas, Texas 75240-2697
          ---------------------------------------------- ------------
               (Address of principal executive offices) (Zip Code)

               Registrant's telephone number, including area code
                                 (972) 233-1700
                                 --------------


                   (Former name or former address, if changed
                              since last report.)

Check  the  appropriate  box  below  if the  Form  8-K  filing  is  intended  to
simultaneously  satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2):

[   ]   Written communications pursuant to Rule 425 under the Securities Act
        (17 CFR 230.425)

[   ]   Soliciting material pursuant to Rule 14a-12 under the Exchange Act
        (17 CFR 240.14a-12)

[   ]   Pre-commencement communications pursuant to Rule 14d-2(b) under the
        Exchange Act (17 CFR 240.14d-2(b))

[   ]   Pre-commencement communications pursuant to Rule 13e-4(c) under the
        Exchange Act (17 CFR 240.13e-4(c))



Item 5.02 Departure  of Directors  or  Principal  Officers;  Election of
          Directors; Appointment of Principal Officers.

     (b) On May 24, 2006,  Mr.  James W. Brown  ceased to hold the  positions of
vice  president and controller of the  registrant.  Mr. Brown has been appointed
vice president,  corporate finance for Titanium Metals  Corporation,  a publicly
held corporation related to the registrant ("TIMET").

     (c) On May 24,  2006,  Mr.  Tim C.  Hafer,  age 44, was  appointed  as vice
president  and  controller  of the  registrant  to serve at the  pleasure of the
registrant's board of directors.  From 2003 to May 24, 2006, Mr. Hafer served as
director - finance and control of the registrant  and of NL Industries,  Inc., a
publicly held corporation  related to the registrant ("NL").  From prior to 2001
to 2003, Mr. Hafer served as an assistant  controller of Valhi, Inc., a publicly
held parent corporation of the registrant ("Valhi"), and Contran Corporation,  a
privately  held  parent  corporation  of the  registrant,  NL,  TIMET  and Valhi
("Contran").  Mr.  Hafer is an employee of Contran and  provides his services to
the registrant under an  intercorporate  services  agreement between Contran and
the registrant.  For a description of the intercorporate services agreement, see
"Certain   Relationships  and  Transactions"  in  the  registrant's  2006  proxy
statement  ("Proxy  Statement")  filed  with the U.S.  Securities  and  Exchange
Commission  on April 13,  2006  (SEC File No.  1-31763),  which  description  is
incorporated herein by reference.

     On May 24,  2006,  Mr.  Hafer  was also  appointed  as vice  president  and
controller  of NL. For a  discussion  of  potential  conflicts  of  interest  of
officers who serve more than one  corporation,  see "Certain  Relationships  and
Transactions" in the Proxy Statement, which discussion is incorporated herein by
reference.


Item 7.01 Regulation FD Disclosure.

         The registrant  hereby furnishes the information set forth in its press
release  issued on May 24, 2006,  a copy of which is attached  hereto as Exhibit
99.1 and incorporated herein by reference.

         The  information,  including the exhibit,  the registrant  furnishes in
this report is not deemed  "filed" for purposes of section 18 of the  Securities
Exchange Act of 1934, as amended,  or otherwise  subject to the  liabilities  of
that  section.  Registration  statements  or  other  documents  filed  with  the
Securities and Exchange  Commission  shall not incorporate  this  information by
reference, except as otherwise expressly stated in such filing.

Item 9.01           Financial Statements and Exhibits.

         (c) Exhibits.

              Item No.          Exhibit Index
              ----------        ----------------------------------------
              99.1              Press Release dated May 24, 2006 issued
                                by the registrant.






                                    SIGNATURE


         Pursuant to the  requirements  of the Securities  Exchange Act of 1934,
the  registrant  has duly  caused  this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                                  KRONOS WORLDWIDE, INC.
                                                  (Registrant)




                                                  By:    /s/ A. Andrew R. Louis
                                                         -----------------------
                                                         A. Andrew R. Louis
                                                         Secretary




Date:  May 26, 2006







                                INDEX TO EXHIBITS


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

99.1              Press Release dated May 24, 2006 issued by the registrant.