<DOCUMENT>
<TYPE>EX-5.1
<SEQUENCE>3
<FILENAME>kwiexh510217.txt
<TEXT>


                                                                    Exhibit 5.1

                            LOCKE LIDDELL & SAPP LLP
                          2200 Ross Avenue, Suite 2200
                               Dallas, Texas 75201

                                February 17, 2005

Kronos Worldwide, Inc.
Three Lincoln Centre
5430 LBJ Freeway, Suite 1700
Dallas, Texas  75240-2697

     Re:  $100,000,000   Aggregate   Offering  Price  of  Securities  of  Kronos
          Worldwide, Inc.

Ladies and Gentlemen:

     We are acting as securities  counsel to Kronos Worldwide,  Inc., a Delaware
corporation  (the "Company"),  in connection with the registration  statement on
Form S-3 (the "Registration Statement") filed by the Company with the Securities
and Exchange  Commission (the "Commission") under the Securities Act of 1933, as
amended (the "Securities  Act"),  relating to the offering from time to time, as
set  forth  in the  prospectus  contained  in the  Registration  Statement  (the
"Prospectus")  and  as to be  set  forth  in  one  or  more  supplements  to the
Prospectus  (each,  a  "Prospectus  Supplement"),   by  the  Company  of  up  to
$100,000,000  aggregate  offering  price of (i) one or more series of  preferred
stock, par value $0.01 per share (the "Preferred Stock"), (ii) common stock, par
value $0.01 per share (the "Common  Stock"),  and/or (iii)  warrants to purchase
Preferred Stock or Common Stock (collectively,  the "Securities Warrants").  The
Preferred Stock,  the Common Stock and the Securities  Warrants are collectively
referred to herein as the  "Securities."  Any Preferred Stock may be convertible
into Common Stock.

     The Securities Warrants will be issued under one or more warrant agreements
(each, a "Securities  Warrant  Agreement")  each to be between the Company and a
financial  institution  identified  therein as warrant  agent (each,  a "Warrant
Agent").

     In our capacity as your counsel in connection  with such  registration,  we
are familiar with the proceedings  taken and proposed to be taken by the Company
in connection with the authorization and issuance of the Securities, and for the
purposes of this opinion, have assumed such proceedings will be timely completed
in the  manner  presently  proposed.  In  addition,  we have made such legal and
factual  examinations  and  inquiries,  including an examination of originals or
copies,  certified  or  otherwise  identified  to  our  satisfaction,   of  such
documents,  corporate  records,  certificates  of  public  officials  and  other
instruments  as we have deemed  necessary or advisable in  connection  with this
opinion,   including  (a)  the  First  Amended  and  Restated   Certificate   of
Incorporation of the Company, (b) the Amended and Restated Bylaws of the Company
and (c) the Registration  Statement,  as amended.  In our  examination,  we have
assumed  the  genuineness  of all  signatures,  the legal  capacity  of  natural
persons,  the  authenticity of all documents  submitted to us as originals,  the
conformity to original  documents of all documents  submitted to us as certified
or photostatic  copies, the authenticity of the originals of such copies and the
authenticity of telegraphic or telephonic  confirmations of public officials and
others. As to facts material to our opinion, we have relied upon certificates or
telegraphic or telephonic  confirmations of public  officials and  certificates,
documents, statements and other information of the Company or representatives or
officers thereof.

     The opinions set forth below address the effect on the subject  transaction
only of the federal  laws of the United  States,  the laws of the State of Texas
and, to the extent  relevant  to the  opinions  expressed  in this  letter,  the
General  Corporation Law of the State of Delaware,  each as presently in effect,
and we express no opinion  with  respect to the  applicability  thereto,  or the
effect thereon, of the laws of any other jurisdiction.  You should be aware that
we are not  admitted to the  practice  of law in the State of  Delaware  and any
opinion  herein as to the laws of such  state are based  solely  upon the latest
unofficial  compilation  of the  corporate  statutes  and case law of such state
available to us.
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         Subject to the foregoing and the other matters set forth herein, it is
our opinion that, as of the date hereof:

     1. The Preferred  Stock has been duly  authorized by the Company,  and when
the Preferred  Stock have been duly  established in accordance with the terms of
the Company's  Certificate of Designation defining the rights and preferences of
the Preferred  Stock,  and  applicable  law, and,  upon  issuance,  delivery and
payment therefor in the manner contemplated by the Registration Statement and/or
the  applicable  Prospectus  Supplement,  the  Preferred  Stock  will be validly
issued, fully paid and nonassessable.

     2. The Common Stock has been duly authorized,  and upon issuance,  delivery
and payment therefor in the manner  contemplated by the  Registration  Statement
and/or the applicable Prospectus Supplement,  will be validly issued, fully paid
and nonassessable.

     3. The Warrant  Agreements  have been duly  authorized  and, when the final
terms thereof have been duly  established,  and when duly executed and delivered
by the Company,  will constitute the legally valid and binding agreements of the
Company,  enforceable  against the Company in accordance  with their  respective
terms.

     4. The Securities  Warrants have been duly  authorized by the Company,  and
when the final terms thereof have been duly established,  and when duly executed
and delivered by the Company and  countersigned by the applicable  Warrant Agent
in accordance  with the applicable  Warrant  Agreement and delivered to and paid
for by the purchasers  thereof in the manner  contemplated  by the  Registration
Statement and/or the applicable Prospectus  Supplement,  will constitute legally
valid and binding obligations of the Company, enforceable against the Company in
accordance with their respective terms.

     The  opinions  set forth  above are  subject to the  following  exceptions,
limitations  and  qualifications:  (i) the  effect  of  bankruptcy,  insolvency,
reorganization,  moratorium  or other  similar  laws now or  hereafter in effect
relating to or affecting the rights and remedies of  creditors;  (ii) the effect
of  general  principles  of  equity  whether  enforcement  is  considered  in  a
proceeding in equity or at law, and the discretion of the court before which any
proceeding therefor may be brought, and (iii) the unenforceability under certain
circumstances  under law or court  decisions  of  provisions  providing  for the
indemnification  of or contribution to a party with respect to a liability where
such indemnification or contribution is contrary to public policy.

     To the extent  that the  obligations  of the  Company  under  each  Warrant
Agreement  may be dependent  upon such  matters,  we assume for purposes of this
opinion that the Warrant Agent is duly organized,  validly  existing and in good
standing under the laws of its  jurisdiction of  organization;  that the Warrant
Agent is duly qualified to engage in the activities  contemplated by the Warrant
Agreement;  that the Warrant  Agreement has been duly  authorized,  executed and
delivered by the Warrant  Agent and  constitutes  the legally  valid and binding
obligation  of the  Warrant  Agent  enforceable  against  the  Warrant  Agent in
accordance  with its terms;  that the Warrant Agent is in compliance,  generally
with respect to acting as a Warrant Agent under the Warrant Agreement,  with all
applicable  laws and  regulations;  and that the Warrant Agent has the requisite
organizational  and legal power and authority to perform its  obligations  under
the Warrant Agreement.

     We consent to your  filing this  opinion as an exhibit to the  Registration
Statement and to the reference to our firm under the caption "Legal  Matters" in
the prospectus included therein. In giving this consent, we do not thereby admit
that we are in the category of persons whose consent is required under Section 7
of the Securities Act or the rules and regulations of the Commission.

     This  opinion is  rendered  only to you and is solely  for your  benefit in
connection with the transactions  covered hereby. This opinion may not be relied
upon by you for any other purpose, or furnished to, quoted to, or relied upon by
any other person, firm or corporation for any purpose, without our prior written
consent.

                            Very truly yours,

                            LOCKE LIDDELL & SAPP LLP

                            By:/s/ Don M. Glendenning
                               ------------------------------------
                               Don M. Glendenning


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