    <SEC-DOCUMENT>0000937556-18-000157-index.html : 20181031
    <SEC-HEADER>0000937556-18-000157.hdr.sgml : 20181031
    <ACCEPTANCE-DATETIME>20181031160819
    ACCESSION NUMBER:		0000937556-18-000157
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		19
    CONFORMED PERIOD OF REPORT:	20181031
    ITEM INFORMATION:		Results of Operations and Financial Condition
    ITEM INFORMATION:		Regulation FD Disclosure
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20181031
    DATE AS OF CHANGE:		20181031

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			MASIMO CORP
    		CENTRAL INDEX KEY:			0000937556
    		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTROMEDICAL & ELECTROTHERAPEUTIC APPARATUS [3845]
    		IRS NUMBER:				330368882
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1229

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-33642
    		FILM NUMBER:		181150389

    	BUSINESS ADDRESS:
    		STREET 1:		52 DISCOVERY
    		CITY:			IRVINE
    		STATE:			CA
    		ZIP:			92618
    		BUSINESS PHONE:		949-297-7000

    	MAIL ADDRESS:
    		STREET 1:		52 DISCOVERY
    		CITY:			IRVINE
    		STATE:			CA
    		ZIP:			92618
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>masi-20181031x8k.htm
    <DESCRIPTION>8-K
    <TEXT>
    Document 1 - file: masi-20181031x8k.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.1
    <SEQUENCE>2
    <FILENAME>masi-20181031xex991.htm
    <DESCRIPTION>EXHIBIT 99.1
    <TEXT>
    Document 2 - file: masi-20181031xex991.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.2
    <SEQUENCE>3
    <FILENAME>q32018supplementalearnin.htm
    <DESCRIPTION>EXHIBIT 99.2
    <TEXT>
    Document 3 - file: q32018supplementalearnin.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.3
    <SEQUENCE>4
    <FILENAME>investorrelationsnongaap.htm
    <DESCRIPTION>EXHIBIT 99.3
    <TEXT>
    Document 4 - file: investorrelationsnongaap.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>investorrelationsnongaap001.jpg
    <TEXT>
    Document 5 - file: investorrelationsnongaap001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>masimologoq32018c.jpg
    <TEXT>
    Document 6 - file: masimologoq32018c.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>masimologoq32018d.jpg
    <TEXT>
    Document 7 - file: masimologoq32018d.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>q32018supplementalearnin001.jpg
    <TEXT>
    Document 8 - file: q32018supplementalearnin001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>q32018supplementalearnin002.jpg
    <TEXT>
    Document 9 - file: q32018supplementalearnin002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>q32018supplementalearnin003.jpg
    <TEXT>
    Document 10 - file: q32018supplementalearnin003.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>q32018supplementalearnin004.jpg
    <TEXT>
    Document 11 - file: q32018supplementalearnin004.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>q32018supplementalearnin005.jpg
    <TEXT>
    Document 12 - file: q32018supplementalearnin005.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>q32018supplementalearnin006.jpg
    <TEXT>
    Document 13 - file: q32018supplementalearnin006.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>q32018supplementalearnin007.jpg
    <TEXT>
    Document 14 - file: q32018supplementalearnin007.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>q32018supplementalearnin008.jpg
    <TEXT>
    Document 15 - file: q32018supplementalearnin008.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>q32018supplementalearnin009.jpg
    <TEXT>
    Document 16 - file: q32018supplementalearnin009.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>17
    <FILENAME>q32018supplementalearnin010.jpg
    <TEXT>
    Document 17 - file: q32018supplementalearnin010.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>q32018supplementalearnin011.jpg
    <TEXT>
    Document 18 - file: q32018supplementalearnin011.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>q32018supplementalearnin012.jpg
    <TEXT>
    Document 19 - file: q32018supplementalearnin012.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>