<SEC-DOCUMENT>0001127602-16-047907.txt : 20160331
<SEC-HEADER>0001127602-16-047907.hdr.sgml : 20160331
<ACCEPTANCE-DATETIME>20160331155711
ACCESSION NUMBER:		0001127602-16-047907
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20160331
FILED AS OF DATE:		20160331
DATE AS OF CHANGE:		20160331

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MDU RESOURCES GROUP INC
		CENTRAL INDEX KEY:			0000067716
		STANDARD INDUSTRIAL CLASSIFICATION:	MINING, QUARRYING OF NONMETALLIC MINERALS (NO FUELS) [1400]
		IRS NUMBER:				410423660
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1200 WEST CENTURY AVENUE
		CITY:			BISMARCK
		STATE:			ND
		ZIP:			58503
		BUSINESS PHONE:		701-530-1059

	MAIL ADDRESS:	
		STREET 1:		1200 WEST CENTURY AVENUE
		CITY:			BISMARCK
		STATE:			ND
		ZIP:			58503

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MONTANA DAKOTA UTILITIES CO
		DATE OF NAME CHANGE:	19850429

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Holaday A Bart
		CENTRAL INDEX KEY:			0001449564

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-03480
		FILM NUMBER:		161543268

	MAIL ADDRESS:	
		STREET 1:		P O BOX 5650
		CITY:			BISMARCK
		STATE:			ND
		ZIP:			58506-5650
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-03-31</periodOfReport>

    <issuer>
        <issuerCik>0000067716</issuerCik>
        <issuerName>MDU RESOURCES GROUP INC</issuerName>
        <issuerTradingSymbol>MDU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001449564</rptOwnerCik>
            <rptOwnerName>Holaday A Bart</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>MDU RESOURCES GROUP, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1200 WEST CENTURY AVENUE</rptOwnerStreet2>
            <rptOwnerCity>BISMARCK</rptOwnerCity>
            <rptOwnerState>ND</rptOwnerState>
            <rptOwnerZipCode>58503</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>57025</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2016-03-31</value>
                <footnoteId id="F2"/>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>893.093</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>19.39</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>893.093</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6584.276</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">1 for 1</footnote>
        <footnote id="F2">Phantom Stock units include units that were accrued through dividends under the Deferred Compensation Plan for Directors.</footnote>
        <footnote id="F3">Units are to be settled in cash after report person's retirement.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Debra S. Anderson, Power of Attorney</signatureName>
        <signatureDate>2016-03-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
