-----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,
 CxQetekicvnFar6HY24M+RCjzo6ZBO6ecFSU/7OoLZiMIZnbE3Ewp4bFrY3nZynr
 lVeiTsQXzcOR7KnxfhcbBA==

<SEC-DOCUMENT>0001061739-06-000001.txt : 20060705
<SEC-HEADER>0001061739-06-000001.hdr.sgml : 20060704
<ACCEPTANCE-DATETIME>20060705123634
ACCESSION NUMBER:		0001061739-06-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060703
FILED AS OF DATE:		20060705
DATE AS OF CHANGE:		20060705

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:		MICRO MOTORS, INC.
		STREET 2:		151 EAST COLUMBINE
		CITY:			SANTA ANA
		STATE:			CA
		ZIP:			92707
		BUSINESS PHONE:		714-241-4411

	MAIL ADDRESS:	
		STREET 1:		MICRO MOTORS INC.
		STREET 2:		151 EAST COLUMBINE
		CITY:			SANTA ANA
		STATE:			CA
		ZIP:			92707

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ISAAC GEORGE J
		CENTRAL INDEX KEY:			0001061739
		STANDARD INDUSTRIAL CLASSIFICATION:	WHOLESALE-MEDICAL, DENTAL & HOSPITAL EQUIPMENT & SUPPLIES [5047]
		STATE OF INCORPORATION:			CO
		FISCAL YEAR END:			0630

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14942
		FILM NUMBER:		06942390

	BUSINESS ADDRESS:	
		STREET 1:		1401 WALNUT ST STE 500
		CITY:			BOULDER
		STATE:			CO
		ZIP:			80302-5333
		BUSINESS PHONE:		3034438165

	MAIL ADDRESS:	
		STREET 1:		1401 WALNUT STREET
		STREET 2:		SUITE 540
		CITY:			BOULDER
		STATE:			CO
		ZIP:			80302
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-07-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001061739</rptOwnerCik>
            <rptOwnerName>ISAAC GEORGE J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>36 WHISPER DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WORCESTER</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01609</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>PDEX Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.74</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-07-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>15000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.74</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2007-01-03</value>
            </exerciseDate>
            <expirationDate>
                <value>2016-07-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Stock Options</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>15000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>164500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <ownerSignature>
        <signatureName>George J. Isaac</signatureName>
        <signatureDate>2006-07-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----