-----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,
 UqbYrn6IsLaSaA3NEAz25Os4JuQuMAURLTj+93BM/mJAd3tgZKLmDmZvZJGIaC6s
 ny/6967P59TmZwFcCQqHzw==

<SEC-DOCUMENT>0001232201-10-000011.txt : 20100413
<SEC-HEADER>0001232201-10-000011.hdr.sgml : 20100413
<ACCEPTANCE-DATETIME>20100413112040
ACCESSION NUMBER:		0001232201-10-000011
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100412
FILED AS OF DATE:		20100413
DATE AS OF CHANGE:		20100413

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HELFET ANTHONY B
		CENTRAL INDEX KEY:			0001248241

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34195
		FILM NUMBER:		10746426

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LAYNE CHRISTENSEN CO
		CENTRAL INDEX KEY:			0000888504
		STANDARD INDUSTRIAL CLASSIFICATION:	CONSTRUCTION SPECIAL TRADE CONTRACTORS [1700]
		IRS NUMBER:				480920712
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0131

	BUSINESS ADDRESS:	
		STREET 1:		1900 SHAWNEE MISSION PKWY
		CITY:			MISSION WOODS
		STATE:			KS
		ZIP:			66205-2001
		BUSINESS PHONE:		9133620510

	MAIL ADDRESS:	
		STREET 1:		1900 SHAWNEE MISSION PKWY
		CITY:			MISSION WOODS
		STATE:			KS
		ZIP:			66205-2001

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	LAYNE INC
		DATE OF NAME CHANGE:	19930328
</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>2010-04-12</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000888504</issuerCik>
        <issuerName>LAYNE CHRISTENSEN CO</issuerName>
        <issuerTradingSymbol>LAYN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001248241</rptOwnerCik>
            <rptOwnerName>HELFET ANTHONY B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1900 SHAWNEE MISSION PKWY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MISSION WOODS</rptOwnerCity>
            <rptOwnerState>KS</rptOwnerState>
            <rptOwnerZipCode>66205</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-04-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1410</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>27.0937</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2379</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>/s/ Jerry W. Fanska, Attorney-in-Fact for Anthony B. Helfet</signatureName>
        <signatureDate>2010-04-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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