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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 S/+xqpy8KqEu+E6FSP5lvg==

<SEC-DOCUMENT>0000032198-09-000037.txt : 20090505
<SEC-HEADER>0000032198-09-000037.hdr.sgml : 20090505
<ACCEPTANCE-DATETIME>20090505181721
ACCESSION NUMBER:		0000032198-09-000037
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090501
FILED AS OF DATE:		20090505
DATE AS OF CHANGE:		20090505

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			O'Connell Thomas W
		CENTRAL INDEX KEY:			0001405149

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-06072
		FILM NUMBER:		09798893

	MAIL ADDRESS:	
		STREET 1:		4302 ROBERTSON BOULEVARD
		CITY:			ALEXANDRIA
		STATE:			VA
		ZIP:			22309

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EMS TECHNOLOGIES INC
		CENTRAL INDEX KEY:			0000032198
		STANDARD INDUSTRIAL CLASSIFICATION:	RADIO & TV BROADCASTING & COMMUNICATIONS EQUIPMENT [3663]
		IRS NUMBER:				581035424
		STATE OF INCORPORATION:			GA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		660 ENGINEERING DRIVE
		CITY:			NORCROSS
		STATE:			GA
		ZIP:			30092
		BUSINESS PHONE:		7702639200

	MAIL ADDRESS:	
		STREET 1:		PO BOX 7700
		CITY:			NORCROSS
		STATE:			GA
		ZIP:			30091-7700

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ELECTROMAGNETIC SCIENCES INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-05-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000032198</issuerCik>
        <issuerName>EMS TECHNOLOGIES INC</issuerName>
        <issuerTradingSymbol>elmg</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001405149</rptOwnerCik>
            <rptOwnerName>O'Connell Thomas W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4302 ROBERTSON BOULEVARD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ALEXANDRIA</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22309</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-05-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>209.97</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>19.05</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>209.97</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1399.48</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>18.45</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-05-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2009-11-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2015-05-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Shares of phantom stock, awarded quarterly for service as a director, become payable upon the reporting person's termination of service as a director, such payments to be made in cash installments on a schedule as elected by the reporting person.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Tom O'Connell</signatureName>
        <signatureDate>2009-05-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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