EXHIBIT 21.1
SUBSIDIARIES
PRESENT SUBSIDIARIES
State or Jurisdiction Percentage of Voting
Entity Name Incorporation Securities Owned
----------- ------------------------- --------------------
Teradyne Assembly Holdings Ltd..................... United Kingdom 100%
Teradyne Assembly Limited.......................... United Kingdom 100%
Teradyne ATE (Wuxi) Co., Ltd....................... Peoples Republic of China 100%
Teradyne Benelux, Inc. (Ltd.)...................... Delaware 100%
Teradyne Canada Limited............................ Canada 100%
Teradyne Connection Systems de Mexico, S.A. de C.V. Mexico 100%
Teradyne Connection Systems SDN BHD................ Malaysia 100%
Teradyne Connections Systems (Shanghai) Co., Ltd... Peoples Republic of China 100%
Teradyne de Costa Rica S.A......................... Costa Rica 100%
Teradyne Diagnostic Solutions Inc.................. Delaware 100%
Teradyne Diagnostic Solutions Limited.............. United Kingdom 100%
Teradyne Diagnostic Solutions GmbH................. Germany 100%
Teradyne EMS Inc................................... Delaware 100%
Teradyne GmbH...................................... Germany 100%
Teradyne Holdings Limited.......................... United Kingdom 100%
Teradyne Limited................................... United Kingdom 100%
Teradyne Hong Kong, Ltd............................ Delaware 100%
Teradyne International, Ltd........................ Barbados 100%
Teradyne Ireland Limited........................... Ireland 100%
Teradyne Italia SrL................................ Italy 100%
Teradyne Japan, Ltd................................ Delaware 100%
Teradyne KK........................................ Japan 100%
Teradyne Korea, Ltd................................ Delaware 100%
Teradyne Leasing, Inc.............................. Massachusetts 100%
Teradyne Malaysia, Ltd............................. Delaware 100%
Teradyne de Mexico, SA de CV....................... Mexico 100%
Teradyne Netherlands BV............................ Netherlands 100%
Teradyne Netherlands, Ltd.......................... Delaware 100%
Teradyne Performance Systems Limited............... United Kingdom 100%
Teradyne Philippines Limited....................... Delaware 100%
Teradyne Realty, Inc............................... Massachusetts 100%
Teradyne SAS....................................... France 100%
Teradyne Scandinavia, Inc.......................... Delaware 100%
Teradyne Singapore, Ltd............................ Delaware 100%
Teradyne Software and Systems Test, Inc............ Delaware 100%
Teradyne Spain, Inc................................ Delaware 100%
Teradyne Taiwan, Ltd............................... Delaware 100%
Teradyne Thailand Inc.............................. Delaware 100%
Aegis Properties Limited........................... United Kingdom 100%
Alternative Delivery Systems Support, Inc.......... North Carolina 100%
Control Automation, Inc............................ Delaware 100%
GenRad, Inc........................................ Massachusetts 100%
Autodiagnos, Inc................................ Delaware 100%
Autodiagnos AB.................................. Sweden 100%
Autodiagnos BV.................................. Netherlands 100%
Autodiagnos GmbH................................ Germany 100%
Autodiagnos LTD................................. United Kingdom 100%
State or Jurisdiction Percentage of Voting
Entity Name Incorporation Securities Owned
----------- ------------------------- --------------------
Autodiagnos UK Limited.......... United Kingdom 100%
GenRad AB....................... Sweden 100%
GenRad GmbH..................... Germany 100%
GenRad Limited.................. United Kingdom 100%
GenRad SA....................... France 100%
GenRad Asia PTE Limited......... Singapore 100%
GenRad Benelux BV............... Netherlands 100%
GenRad Canada Limited........... Canada 100%
GenRad China Limited............ Peoples Republic of China 100%
GenRad Europe Limited........... United Kingdom 100%
GenRad Holdings Limited......... United Kingdom 100%
GenRad Ireland LTD.............. Ireland 100%
GenRad Mexico, Inc.............. Delaware 100%
Mastertech Automotive Ltd....... United Kingdom 100%
Mitron Europe Limited........... United Kingdom 100%
Motor Industry Services Limited. United Kingdom 100%
Herco Technology Corp.............. California 100%
Kinetrix, Inc...................... Delaware 100%
Megatest HK Ltd.................... Hong Kong 100%
Tarstock Limited................... Ireland 100%
Teradyne Philippines Ltd........... California 100%
Perception Laminates, Inc.......... California 100%
Softbridge, Inc.................... Delaware 100%
TCMS, Inc.......................... Delaware 100%
Zehntel Holdings, Inc.............. California 100%
1000 Washington, Inc............... Massachusetts 100%