WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.

<TABLE> <S> <C>

<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE BALANCE
SHEETS, STATEMENTS OF OPERATIONS AND STATEMENTS OF CASH FLOWS OF THORATEC
LABORATORIES CORPORATION AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF SECURITIES AND EXCHANGE ACT
OF 1934 FOR THE QUARTERLY PERIOD ENDED OCTOBER 2, 1999.
</LEGEND>

<S>                             <C>
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          JAN-01-2000
<PERIOD-START>                             JAN-03-1999
<PERIOD-END>                               OCT-02-1999
<CASH>                                       1,314,876
<SECURITIES>                                 2,120,138
<RECEIVABLES>                                3,746,327
<ALLOWANCES>                                         0
<INVENTORY>                                  7,046,487
<CURRENT-ASSETS>                            14,528,416
<PP&E>                                      11,810,989
<DEPRECIATION>                             (2,417,084)
<TOTAL-ASSETS>                              24,949,482
<CURRENT-LIABILITIES>                        3,341,335
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                    72,909,017
<OTHER-SE>                                (52,226,355)
<TOTAL-LIABILITY-AND-EQUITY>                24,949,482
<SALES>                                      5,075,597
<TOTAL-REVENUES>                             5,232,861
<CGS>                                        2,324,527
<TOTAL-COSTS>                                2,324,527
<OTHER-EXPENSES>                             3,810,588
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                              (902,254)
<INCOME-TAX>                                         0
<INCOME-CONTINUING>                          (902,254)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                 (902,254)
<EPS-BASIC>                                     (0.04)
<EPS-DILUTED>                                   (0.04)

[ARTICLE] 5
[LEGEND]
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE BALANCE
SHEETS, STATEMENTS OF OPERATIONS AND STATEMENTS OF CASH FLOWS OF THORATEC
LABORATORIES CORPORATION AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
QUARTERLY REPORTS PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES AND EXCHANGE
ACT OF 1934 FOR THE QUARTERLY PERIOD ENDED OCTOBER 2, 1999.
[/LEGEND]

<S>                             <C>
[PERIOD-TYPE]                   9-MOS
[FISCAL-YEAR-END]                          JAN-01-2000
[PERIOD-START]                             JAN-03-1999
[PERIOD-END]                               OCT-02-1999
[CASH]                                       1,314,876
[SECURITIES]                                 2,120,138
[RECEIVABLES]                                3,746,327
[ALLOWANCES]                                         0
[INVENTORY]                                  7,046,487
[CURRENT-ASSETS]                            14,528,416
[PP&E]                                      11,810,989
[DEPRECIATION]                             (2,417,084)
[TOTAL-ASSETS]                              24,949,482
[CURRENT-LIABILITIES]                        3,341,335
[BONDS]                                              0
[PREFERRED-MANDATORY]                                0
[PREFERRED]                                          0
[COMMON]                                    72,909,017
[OTHER-SE]                                (52,226,355)
[TOTAL-LIABILITY-AND-EQUITY]                24,949,482
[SALES]                                     15,342,748
[TOTAL-REVENUES]                            15,872,240
[CGS]                                        6,333,291
[TOTAL-COSTS]                                6,333,291
[OTHER-EXPENSES]                            10,829,715
[LOSS-PROVISION]                                     0
[INTEREST-EXPENSE]                                   0
[INCOME-PRETAX]                            (1,290,766)
[INCOME-TAX]                                         0
[INCOME-CONTINUING]                        (1,290,766)
[DISCONTINUED]                                       0
[EXTRAORDINARY]                                      0
[CHANGES]                                            0
[NET-INCOME]                               (1,290,766)
[EPS-BASIC]                                   (0.06)
[EPS-DILUTED]                                   (0.06)


</TABLE>