<ARTICLE>                     5
<LEGEND>
     This schedule  contains summary  financial  information  extracted from the
condensed  consolidated  balance  sheet at  October  3,  1999 and the  condensed
consolidated  statement of income for the nine months ended  October 3, 1999 and
is qualified in its entirety by reference to such financial staements.
</LEGEND>
<CIK>          0000097210
<NAME>         Teradyne, Inc.
<MULTIPLIER>                                   1,000
<CURRENCY>                                     U.S. Dollars

                             
<PERIOD-TYPE>                  9-Mos
<FISCAL-YEAR-END>                              DEC-31-1999
<PERIOD-START>                                 JAN-01-1999
<PERIOD-END>                                   OCT-03-1999
<EXCHANGE-RATE>                                1.00
<CASH>                                         121,205
<SECURITIES>                                   102,624
<RECEIVABLES>                                  318,796
<ALLOWANCES>                                   3,843
<INVENTORY>                                    282,631
<CURRENT-ASSETS>                               904,795
<PP&E>                                         945,833
<DEPRECIATION>                                 476,754
<TOTAL-ASSETS>                                 1,534,389
<CURRENT-LIABILITIES>                          366,924
<BONDS>                                        0
<PREFERRED-MANDATORY>                          0
<PREFERRED>                                    0
<COMMON>                                       21,405
<OTHER-SE>                                     1,119,665
<TOTAL-LIABILITY-AND-EQUITY>                   1,534,389
<SALES>                                        1,242,397
<TOTAL-REVENUES>                               1,242,397
<CGS>                                          738,097
<TOTAL-COSTS>                                  1,087,318
<OTHER-EXPENSES>                               0
<LOSS-PROVISION>                               0
<INTEREST-EXPENSE>                             1,121
<INCOME-PRETAX>                                166,372
<INCOME-TAX>                                   49,912
<INCOME-CONTINUING>                            116,460
<DISCONTINUED>                                 0
<EXTRAORDINARY>                                0
<CHANGES>                                      0
<NET-INCOME>                                   116,460
<EPS-BASIC>                                  0.68
<EPS-DILUTED>                                  0.65