<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM CHIRON
CORPORATION'S CONSOLIDATED BALANCE SHEET DATED DECEMBER 31, 1996 AND
CONSOLIDATED STATEMENT OF OPERATIONS FOR THE YEAR ENDED DECEMBER 31, 1996 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000

<S>                             <C>
<PERIOD-TYPE>                   12-MOS
<FISCAL-YEAR-END>                          DEC-31-1996<F6>
<PERIOD-START>                             JAN-01-1996
<PERIOD-END>                               DEC-31-1996<F6>
<CASH>                                          68,114
<SECURITIES>                                    60,721<F1>
<RECEIVABLES>                                  351,971
<ALLOWANCES>                                    20,692
<INVENTORY>                                    180,534
<CURRENT-ASSETS>                               696,768
<PP&E>                                         796,821
<DEPRECIATION>                                 213,217
<TOTAL-ASSETS>                               1,688,670
<CURRENT-LIABILITIES>                          473,169
<BONDS>                                        419,589<F2>
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         1,707
<OTHER-SE>                                     763,148<F3>
<TOTAL-LIABILITY-AND-EQUITY>                 1,688,670
<SALES>                                      1,004,827
<TOTAL-REVENUES>                             1,312,844
<CGS>                                          438,885
<TOTAL-COSTS>                                  438,885
<OTHER-EXPENSES>                               386,014<F4>
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              30,741<F7>
<INCOME-PRETAX>                                 79,974<F5>
<INCOME-TAX>                                    24,829
<INCOME-CONTINUING>                             55,145
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    55,145
<EPS-PRIMARY>                                     0.31<F8>
<EPS-DILUTED>                                     0.31<F8>
<FN>
<F1> CONSISTS OF BOTH SHORT-TERM AND NON-CURRENT INVESTMENTS IN MARKETABLE DEBT
     SECURITIES.

<F2> CONSISTS OF CONVERTIBLE SUBORDINATED DEBENTURES, CAPITAL LEASE OBLIGATIONS,
     AND NOTES PAYABLE, NET OF CURRENT MATURITIES.

<F3> CONSISTS OF ADDITIONAL PAID-IN-CAPITAL, ACCUMULATED DEFICIT, CUMULATIVE
     FOREIGN CURRENCY TRANSLATION ADJUSTMENT, UNREALIZED GAIN FROM INVESTMENTS
     AND NOTES RECEIVABLE FROM STOCK SALES.

<F4> CONSISTS OF RESEARCH AND DEVELOPMENT AND OTHER OPERATING EXPENSES.

<F5> INCLUDES A $12.2 MILLION GAIN FROM THE SALE OF A PARTNERSHIP INTEREST
     REFLECTED IN OTHER EXPENSE, NET; AND $6.9 MILLION IN ROYALTIES RELATED TO
     PRIOR PERIOD SALES RESULTING FROM A SETTLEMENT, REFLECTED IN EQUITY IN
     EARNINGS OF UNCONSOLIDATED JOINT BUSINESSES.

<F6> ACTUAL FISCAL YEAR END AND PERIOD END WAS DEC-29-1996, BUT FOR PRESENTATION
     PURPOSES DATES USED IN THE CONSOLIDATED FINANCIAL STATEMENTS AND NOTES
     REFER TO THE CALENDAR MONTH END (DEC-31-1996).

<F7> CONSISTS OF $18.1 MILLION OF INTEREST EXPENSE ON CONVERTIBLE
     DEBENTURES, $3.4 MILLION OF INTEREST EXPENSE ON RELATED PARTY
     PAYABLE AND $9.2 MILLION OF OTHER INTEREST EXPENSE.

<F8> THE COMPANY DECLARED A 4-FOR-1 STOCK SPLIT EFFECTIVE AUG-02-1996.
     PRIOR FINANCIAL DATA SCHEDULES HAVE NOT BEEN RESTATED FOR THIS
     RECAPITALIZATION.


</TABLE>