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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 FGn6E123QPxWtehhXThPHFv4M9RQKwNJ0XxilB1h3LGszmkkIkxRs3tAWQ2VxSXM
 ZOz3s+5mj4PfqFTg6C5IiQ==

<SEC-DOCUMENT>0001088479-05-000002.txt : 20050630
<SEC-HEADER>0001088479-05-000002.hdr.sgml : 20050630
<ACCEPTANCE-DATETIME>20050630104633
ACCESSION NUMBER:		0001088479-05-000002
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20041119
FILED AS OF DATE:		20050630
DATE AS OF CHANGE:		20050630

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NYFIX INC
		CENTRAL INDEX KEY:			0000099047
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMPUTER INTEGRATED SYSTEMS DESIGN [7373]
		IRS NUMBER:				061344888
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		333 LUDLOW STREET
		CITY:			STAMFORD
		STATE:			CT
		ZIP:			06902
		BUSINESS PHONE:		2034258000

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TRINITECH SYSTEMS INC
		DATE OF NAME CHANGE:	19940404

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TRANS AIRE ELECTRONICS INC
		DATE OF NAME CHANGE:	19910916

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WAJNERT THOMAS C
		CENTRAL INDEX KEY:			0001088479

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-21324
		FILM NUMBER:		05927079

	MAIL ADDRESS:	
		STREET 1:		401 NORTH MAIN STREET
		CITY:			WINSTON SALEM
		STATE:			NC
		ZIP:			27102
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2004-11-19</periodOfReport>

    <dateOfOriginalSubmission>2004-10-20</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000099047</issuerCik>
        <issuerName>NYFIX INC</issuerName>
        <issuerTradingSymbol>NYFXE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001088479</rptOwnerCik>
            <rptOwnerName>WAJNERT THOMAS C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NYFIX, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>333 LUDLOW STREET</rptOwnerStreet2>
            <rptOwnerCity>STAMFORD</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06902</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.03</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-11-19</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>70000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-11-19</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>70000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>70000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Options vest 25,000 on 04/19/2005, 15,000 on 10/19/2005, 15,000 on 10/19/2006 and 15,000 on 10/19/2007</footnote>
        <footnote id="F2">Not applicable</footnote>
    </footnotes>

    <remarks>Transaction date earlier reported as 10/19/2004, as described in the Annual Report on Form 10-K for the year ended December 31, 2004, filed by NYFIX,Inc.</remarks>

    <ownerSignature>
        <signatureName>Brian Bellardo, by Power of Attorney</signatureName>
        <signatureDate>2005-06-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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