-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 DB+ONRxAc5QhYvW1NO98KzDEH2HZThVwjnUVlo0CbhZltEyGERlcq4bexaPYAoaf
 3WZv+FU9XI0ZaLYxvuxb0Q==

<SEC-DOCUMENT>0001061060-04-000010.txt : 20040405
<SEC-HEADER>0001061060-04-000010.hdr.sgml : 20040405
<ACCEPTANCE-DATETIME>20040405185847
ACCESSION NUMBER:		0001061060-04-000010
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040401
FILED AS OF DATE:		20040405

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NANOPHASE TECHNOLOGIES CORPORATION
		CENTRAL INDEX KEY:			0000883107
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS PRIMARY METAL PRODUCTS [3390]
		IRS NUMBER:				363687863
		STATE OF INCORPORATION:			IL
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		453 COMMERCE ST
		CITY:			BURR RIDGE
		STATE:			IL
		ZIP:			60521
		BUSINESS PHONE:		6303231200

	MAIL ADDRESS:	
		STREET 1:		453 COMMERCE STREET
		CITY:			BURR RIDGE
		STATE:			IL
		ZIP:			60521

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SPURGEON CORP
		CENTRAL INDEX KEY:			0001061060
		STATE OF INCORPORATION:			IL
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22333
		FILM NUMBER:		04718872

	BUSINESS ADDRESS:	
		STREET 1:		290 S COUNTY FARM RD
		STREET 2:		THIRD FL
		CITY:			WHEATON
		STATE:			IL
		ZIP:			60187
		BUSINESS PHONE:		6305887200

	MAIL ADDRESS:	
		STREET 1:		290 S COUNTY FARM RD
		STREET 2:		THIRD FL
		CITY:			WHEATON
		STATE:			IL
		ZIP:			60187
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-04-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000883107</issuerCik>
        <issuerName>NANOPHASE TECHNOLOGIES CORPORATION</issuerName>
        <issuerTradingSymbol>NANX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001061060</rptOwnerCik>
            <rptOwnerName>SPURGEON CORP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>290 S COUNTY FARM RD</rptOwnerStreet1>
            <rptOwnerStreet2>THIRD FL</rptOwnerStreet2>
            <rptOwnerCity>WHEATON</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60187</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <transactionDate>
                <value>2004-04-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8700</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.45</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3402291</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>*</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">*As General Partner of Grace Brothers, Ltd. which owns 2,685,195 shares and as General Partner of Grace Investments, Ltd. which owns 717,096 shares.</footnote>
        <footnote id="F2">*This is a continuing Form 4 reflecting the remaining transactions from a previous filng.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>David J. Allen, Vice President</signatureName>
        <signatureDate>2004-04-05</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----