<ARTICLE>           5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THERMEDICS
INC.'S REPORT ON FORM 10-Q FOR THE PERIOD ENDED OCTOBER 3, 1998 AND IS QUALIFIED
IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER>        1,000
       
                              
<PERIOD-TYPE>                                 9-MOS
<FISCAL-YEAR-END>                             JAN-02-1999
<PERIOD-END>                                  OCT-03-1998
<CASH>                                                119,543
<SECURITIES>                                           74,152
<RECEIVABLES>                                          67,665
<ALLOWANCES>                                            5,049
<INVENTORY>                                            65,463
<CURRENT-ASSETS>                                      337,546
<PP&E>                                                 62,089
<DEPRECIATION>                                         39,687
<TOTAL-ASSETS>                                        559,019
<CURRENT-LIABILITIES>                                 104,950
<BONDS>                                               122,678
<PREFERRED-MANDATORY>                                       0
<PREFERRED>                                                 0
<COMMON>                                                4,174
<OTHER-SE>                                            239,434
<TOTAL-LIABILITY-AND-EQUITY>                          559,019
<SALES>                                               233,887
<TOTAL-REVENUES>                                      233,887
<CGS>                                                 121,594
<TOTAL-COSTS>                                         121,594
<OTHER-EXPENSES>                                       19,543
<LOSS-PROVISION>                                          569
<INTEREST-EXPENSE>                                      4,067
<INCOME-PRETAX>                                        32,088
<INCOME-TAX>                                           12,604
<INCOME-CONTINUING>                                    14,920
<DISCONTINUED>                                              0
<EXTRAORDINARY>                                         4,638
<CHANGES>                                                   0
<NET-INCOME>                                           19,558
<EPS-PRIMARY>                                            0.48
<EPS-DILUTED>                                            0.46