-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 IquPlNkeHyHRJsj+OMfmOtgW09vT+rVDtlDXgl8WQqWRE4xWwsySSOkW0qOsiBW+
 beeEonRexlLicGM9rya+RQ==

<SEC-DOCUMENT>0000859360-03-000075.txt : 20031022
<SEC-HEADER>0000859360-03-000075.hdr.sgml : 20031022
<ACCEPTANCE-DATETIME>20031022103535
ACCESSION NUMBER:		0000859360-03-000075
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031020
FILED AS OF DATE:		20031022

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LEGATO SYSTEMS INC
		CENTRAL INDEX KEY:			0000859360
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				943077394
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3210 PORTER DR
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94304
		BUSINESS PHONE:		4158126000

	MAIL ADDRESS:	
		STREET 1:		3210 PORTER DRIVE
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94304

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHAPPELL JAMES P
		CENTRAL INDEX KEY:			0001225158

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26130
		FILM NUMBER:		03951059

	BUSINESS ADDRESS:	
		STREET 1:		C/O LEGATO SYSTEMS INC
		STREET 2:		2350 W EL CAMINO REAL
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94040
		BUSINESS PHONE:		94040

	MAIL ADDRESS:	
		STREET 1:		2350 W EL CAMINO REAL
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94040
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2003-10-20</periodOfReport>


    <notSubjectToSection16>1</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000859360</issuerCik>
        <issuerName>LEGATO SYSTEMS INC</issuerName>
        <issuerTradingSymbol>LGTO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001225158</rptOwnerCik>
            <rptOwnerName>CHAPPELL JAMES P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2350 W EL CAMINO REAL</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MOUNTAIN VIEW</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94040</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior VP</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2003-04-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>U</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2264</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.111</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>107827</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Qualified 423 Plan</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>Vijay Biligiri</signatureName>
        <signatureDate>2003-10-22</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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