-----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,
 KNB6xFQ2T1BwnyCDWb11Mb+Ozggmb/M0K8Syu1m/1Ju0Oexpdu43k2O8gKO166JA
 E7Ze5cROk5zEEH1xPha1HQ==

<SEC-DOCUMENT>0000099047-07-000016.txt : 20071213
<SEC-HEADER>0000099047-07-000016.hdr.sgml : 20071213
<ACCEPTANCE-DATETIME>20071213170606
ACCESSION NUMBER:		0000099047-07-000016
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20071211
FILED AS OF DATE:		20071213
DATE AS OF CHANGE:		20071213

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GORMAN LON
		CENTRAL INDEX KEY:			0001186007

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-21324
		FILM NUMBER:		071305132

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		4156277000

	MAIL ADDRESS:	
		STREET 1:		120 KEARNY STREET
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94108

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:		100 WALL STREET
		STREET 2:		26TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10005
		BUSINESS PHONE:		212-809-3542

	MAIL ADDRESS:	
		STREET 1:		100 WALL STREET
		STREET 2:		26TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10005

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-12-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001186007</rptOwnerCik>
            <rptOwnerName>GORMAN LON</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NYFIX, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>100 WALL STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10005</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.3</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-12-11</value>
                <footnoteId id="F1"/>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>350000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2017-10-23</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>350000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>350000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option grant was approved by the Board of Directors of NYFIX, Inc. on October 23, 2007 subject to stockholder approval of the equity compensation plan under which the option was granted.  NYFIX stockholders approved the plan on December 11, 2007.</footnote>
        <footnote id="F2">Subject to the condition noted in footnote 1, which was satisfied on December 11, 2007, the option vests and becomes exercisable as to 27.0834% of the shares on October 23, 2007, and as to 2.0833% of the shares on the fourth day of each month thereafter through and including September 4, 2010.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Brian Bellardo, by Power of Attorney</signatureName>
        <signatureDate>2007-12-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----