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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0001257640-10-000018.txt : 20100622
<SEC-HEADER>0001257640-10-000018.hdr.sgml : 20100622
<ACCEPTANCE-DATETIME>20100622183127
ACCESSION NUMBER:		0001257640-10-000018
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20100618
FILED AS OF DATE:		20100622
DATE AS OF CHANGE:		20100622

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SIMMONS HAROLD C
		CENTRAL INDEX KEY:			0001037854
		STATE OF INCORPORATION:			TX
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31763
		FILM NUMBER:		10911501

	MAIL ADDRESS:	
		STREET 1:		THREE LINCOLN CENTRE
		STREET 2:		5430 LBJ FREEWAY STE 1700
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75240-2697

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KRONOS WORLDWIDE INC
		CENTRAL INDEX KEY:			0001257640
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL INORGANIC CHEMICALS [2810]
		IRS NUMBER:				760294959
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		5430 LBJ FREEWAY
		STREET 2:		SUITE 1700
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75240
		BUSINESS PHONE:		9722331700

	MAIL ADDRESS:	
		STREET 1:		5430 LBJ FREEWAY
		STREET 2:		SUITE 1700
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75240

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	KRONOS INC
		DATE OF NAME CHANGE:	20030730
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-06-18</periodOfReport>

    <issuer>
        <issuerCik>0001257640</issuerCik>
        <issuerName>KRONOS WORLDWIDE INC</issuerName>
        <issuerTradingSymbol>KRO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001037854</rptOwnerCik>
            <rptOwnerName>SIMMONS HAROLD C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5430 LBJ FREEWAY, SUITE 1700</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75240</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman of the Board</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock $0.01 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2010-06-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>400</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>18.70</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>242109</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock $0.01 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2010-06-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>18.72</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>242409</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock $0.01 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>28995021</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Valhi</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock $0.01 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17609635</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by NL</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock $0.01 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>79567</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by TFMC</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock $0.01 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>54856</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Spouse</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock $0.01 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2686</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Contran</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Directly held by Valhi, Inc.  See the Additional Information filed as Exhibit 99 to this statement for a description of the relationship to the reporting person.</footnote>
        <footnote id="F2">Directly held by NL Industries, Inc. See the Additional Information filed as Exhibit 99 to this statement for a description of the relationship to the reporting person.</footnote>
        <footnote id="F3">Directly held by TIMET Finance Management Company.  See the Additional Information filed as Exhibit 99 to this statement for a description of the relationship to the reporting person.</footnote>
        <footnote id="F4">Directly held by the reporting person's spouse.  The reporting person disclaims beneficial ownership of, and a pecuniary interest in, any shares of the issuer's common stock that his spouse holds.</footnote>
        <footnote id="F5">Directly held by Contran Corporation.  See the Additional Information filed as Exhibit 99 to this statement for a description of the relationship to the reporting person.</footnote>
    </footnotes>

    <remarks>Exhibit Index
Exhibit 99 Additional Information</remarks>

    <ownerSignature>
        <signatureName>A. Andrew R. Louis, Attorney-in-fact, for Harold C. Simmons</signatureName>
        <signatureDate>2010-06-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99
<SEQUENCE>2
<FILENAME>f4kro100618hcs.htm
<DESCRIPTION>ADDITIONAL INFORMATION
<TEXT>
<HTML><BODY><PRE>f4kro100618hcs.txt





Exhibit 99 Additional Information



 Valhi, Inc. ("Valhi"), NL Industries, Inc. ("NL"), Harold C. Simmons,

TIMET Finance Management Company ("TFMC"), Harold C. Simmons' spouse and Contran

Corporation ("Contran") are the holders of 59.2%, 36.0%, 0.5%, 0.2%, 0.1% and

less than 0.1% respectively, of the outstanding shares of common stock, par

value $0.01 per share ("Common Stock"), of the issuer.



 Titanium Metals Corporation ("TIMET") directly owns 100% of the

outstanding common stock of TFMC. Valhi Holding Company ("VHC"), Harold C.

Simmons' spouse, The Combined Master Retirement Trust (the "CMRT"), Harold C.

Simmons, NL, Contran, Valhi, COAM Company ("COAM"), the Harold Simmons

Foundation, Inc. (the "Foundation") and The Annette Simmons Grandchildren's

Trust (the "Grandchildren's Trust") are the holders of approximately 25.0%,

11.8%, 8.6%, 4.1%, 0.8%, 0.5%, 0.5%, 0.3%, less than 0.1% and less than 0.1%,

respectively, of the outstanding common stock of TIMET. NL's percentage

ownership of TIMET common stock includes 0.3% directly held by a subsidiary of

NL.



 Valhi and TFMC are the direct holders of approximately 83.0% and 0.5%,

respectively, of the outstanding common stock of NL.  VHC, TFMC, the Foundation,

the Contran Amended and Restated Deferred Compensation Trust (the "CDCT"),

Harold C. Simmons' spouse, Harold C. Simmons, the CMRT, Contran and the

Grandchildren's Trust are the direct holders of 92.3%, 1.1%, 0.9%, 0.3%, 0.2%,

0.2%, 0.1%, less than 0.1% and less than 0.1%respectively, of the outstanding

common stock of Valhi. Dixie Rice Agricultural Corporation, Inc. ("Dixie Rice")

is the direct holder of 100% of the outstanding common stock of VHC. Contran is

the holder of 100% of the outstanding common stock of Dixie Rice.



 Substantially all of Contran's outstanding voting stock is held by

trusts established for the benefit of certain children and grandchildren of

Harold C. Simmons (the "Trusts"), of which Mr. Simmons is the sole trustee,

or is held by Mr. Simmons or persons or entities related to Mr. Simmons. As

sole trustee of the Trusts, Mr. Simmons has the power to vote and direct the

disposition of the shares of Contran stock held by the Trusts. Mr. Simmons

disclaims beneficial ownership of, and a pecuniary interest in, all Contran

shares that the Trusts hold.



 The Foundation directly holds less than 0.1% of the outstanding shares of

TIMET common stock and 0.9% of the outstanding shares of Valhi common stock. The

Foundation is a tax-exempt foundation organized for charitable purposes. Harold

C. Simmons is the chairman of the board of the Foundation.



 The CMRT directly holds approximately 8.6% of the outstanding shares of

TIMET common stock and 0.1% of the outstanding shares of Valhi common stock.

Contran sponsors the CMRT, which permits the collective investment by master

trusts that maintain the assets of certain employee benefit plans Contran and

related companies adopt. Harold C. Simmons is the sole trustee of the CMRT

and a member of the trust investment committee for the CMRT. Contran's board

of directors selects the trustee and members of the trust investment

committee for the CMRT. Mr. Simmons is a participant in one or more of the

employee benefit plans that invest through the CMRT.



 The CDCT directly holds approximately 0.3% of the outstanding shares of

Valhi common stock.  U.S. Bank National Association serves as the trustee of

the CDCT.  Contran established the CDCT as an irrevocable "rabbi trust" to

assist Contran in meeting certain deferred compensation obligations that it

owes to Harold C. Simmons.  If the CDCT assets are insufficient to satisfy

such obligations, Contran is obligated to satisfy the balance of such

obligations as they come due.  Pursuant to the terms of the CDCT, Contran (i)

retains the power to vote the shares of Valhi common stock held directly by

the CDCT, (ii) retains dispositive power over such shares and (iii) may be

deemed the indirect beneficial owner of such shares.



 Contran, Valhi and Southwest Louisiana Land LLC ("Southwest") directly

hold all of the partnership interests of COAM.  Contran is the sole member of

Southwest.



 Harold C. Simmons is the chairman of the board of each of the issuer,

Valhi, TIMET, VHC, Dixie Rice, Southwest and Contran and the chairman of the

board and chief executive officer of NL.



 By virtue of the holding of the offices, the stock ownership and his

services as trustee, all as described above, (a) Harold C. Simmons may be

deemed to control such entities and (b) Mr. Simmons and certain of such

entities may be deemed to possess indirect beneficial ownership of shares

directly held by certain of such other entities. However, Mr. Simmons

disclaims such beneficial ownership of, and a pecuniary interest in, the

shares beneficially owned directly or indirectly by any of such entities,

except to the extent of his vested beneficial interest, if any, in shares

held by the CDCT or the CMRT. Mr. Harold Simmons disclaims beneficial

ownership of, and a pecuniary interest in, all shares of Common Stock that

Valhi, NL, TFMC or Contran directly holds.



 Harold C. Simmons' spouse is the direct owner of 54,856 shares of

Common Stock, 292,225 shares of NL common stock, 21,115,875 shares of TIMET

common stock and 203,065 shares of Valhi common stock. Mr. Simmons may be

deemed to share indirect beneficial ownership of such shares. Mr. Simmons

disclaims all such beneficial ownership.



 Harold C. Simmons directly holds 242,409 shares of Common Stock, 883,100

shares of NL common stock, 7,422,787 shares of TIMET common stock and 183,082

shares of Valhi common stock.



 A trust, of which Harold C. Simmons and his spouse are trustees and the

beneficiaries are the grandchildren of his spouse, is the direct holder of

15,432 shares of TIMET common stock and 31,800 shares of Valhi common stock.

Mr. Simmons, as co-trustee of this trust, has the power to vote and direct

the disposition of the shares of Valhi common stock the trust holds. Mr.

Simmons disclaims beneficial ownership of, and a pecuniary interest in, any

shares that this trust holds.



 NL and a subsidiary of NL directly own 3,604,790 and 1,186,200 shares

of Valhi common stock, respectively. As already discussed, Valhi directly holds

83.0% of the outstanding shares of NL common stock. Pursuant to Delaware law,

Valhi treats the shares of Valhi common stock that NL and the subsidiary of NL

own as treasury stock for voting purposes. For the purposes of the percentage

calculations herein, such shares are not deemed outstanding.



</PRE></BODY></HTML>
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