<SUBMISSION>
<ACCESSION-NUMBER>0001181431-07-058662
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20070921
<FILING-DATE>20070924
<DATE-OF-FILING-DATE-CHANGE>20070924
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>OSI SYSTEMS INC
<CIK>0001039065
<ASSIGNED-SIC>3674
<IRS-NUMBER>330238801
<STATE-OF-INCORPORATION>CA
<FISCAL-YEAR-END>0630
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>12525 CHADRON AVE
<CITY>HAWTHORNE
<STATE>CA
<ZIP>90250
<PHONE>3109780516
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>12525 CHADRON AVENUE
<CITY>HAWTHORNE
<STATE>CA
<ZIP>90250
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>CHOPRA DEEPAK
<CIK>0001047058
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-23125
<FILM-NUMBER>071132143
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O OSI SYSTEMS INC
<STREET2>12525 CHADRON AVE
<CITY>HAWTHORNE
<STATE>CA
<ZIP>70250
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET2>12525 CHADRON AVE
<CITY>HAWTHORNE
<STATE>CA
<ZIP>90250
</MAIL-ADDRESS>
<FORMER-NAME>
<FORMER-CONFORMED-NAME>CHAMBERLAIN SALLY F ECHOPRA DEEPAK
<DATE-CHANGED>19970930
</FORMER-NAME>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd173164.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-09-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001039065</issuerCik>
        <issuerName>OSI SYSTEMS INC</issuerName>
        <issuerTradingSymbol>OSIS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001047058</rptOwnerCik>
            <rptOwnerName>CHOPRA DEEPAK</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12525 CHADRON AVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HAWTHORNE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90250</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-09-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>50000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.0757</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>625440</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-09-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.1204</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>225000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-09-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.1204</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>215000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Shares owned by The Chandi Chopra Trust. Mr. Chopra is the co trustee of such trust.</footnote>
        <footnote id="F2">Shares owned by The Deepika Chopra Trust. Mr. Chopra is the co trustee of such trust.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Deepak Chopra</signatureName>
        <signatureDate>2007-09-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
