<SEC-DOCUMENT>0001478067-11-000005.txt : 20111227
<SEC-HEADER>0001478067-11-000005.hdr.sgml : 20111226
<ACCEPTANCE-DATETIME>20111227150509
ACCESSION NUMBER:		0001478067-11-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20111222
FILED AS OF DATE:		20111227
DATE AS OF CHANGE:		20111227

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Swenson Nicholas John
		CENTRAL INDEX KEY:			0001478067

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14942
		FILM NUMBER:		111282130

	MAIL ADDRESS:	
		STREET 1:		3033 EXCELSIOR BOULEVARD
		STREET 2:		SUITE 560
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55416

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PRO DEX INC
		CENTRAL INDEX KEY:			0000788920
		STANDARD INDUSTRIAL CLASSIFICATION:	SURGICAL & MEDICAL INSTRUMENTS & APPARATUS [3841]
		IRS NUMBER:				841261240
		STATE OF INCORPORATION:			CO
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		2361 MCGAW AVENUE
		CITY:			IRVINE
		STATE:			CA
		ZIP:			92614
		BUSINESS PHONE:		949-769-3200

	MAIL ADDRESS:	
		STREET 1:		2361 MCGAW AVENUE
		CITY:			IRVINE
		STATE:			CA
		ZIP:			92614
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-12-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000788920</issuerCik>
        <issuerName>PRO DEX INC</issuerName>
        <issuerTradingSymbol>PDEX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001478067</rptOwnerCik>
            <rptOwnerName>Swenson Nicholas John</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3033 EXCELSIOR BOULEVARD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 560</rptOwnerStreet2>
            <rptOwnerCity>MINNEAPOLIS</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55416</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>PDEX</value>
            </securityTitle>
            <transactionDate>
                <value>2011-12-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>30400</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.301</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>456322</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Purchased in range from $2.31 to $2.23.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Nick Swenson</signatureName>
        <signatureDate>2011-12-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
