<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM CHIRON
CORPORATION'S CONSOLIDATED BALANCE SHEET DATED DECEMBER 31, 1995 AND
CONSOLIDATED STATEMENT OF OPERATIONS FOR THE YEAR ENDED DECEMBER 31, 1995 AND
IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<RESTATED> 
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1995
<PERIOD-START>                             JAN-01-1995
<PERIOD-END>                               DEC-31-1995
<CASH>                                          74,318
<SECURITIES>                                   149,899<F1>
<RECEIVABLES>                                  304,303
<ALLOWANCES>                                    18,524
<INVENTORY>                                    165,941
<CURRENT-ASSETS>                               637,003
<PP&E>                                         658,579
<DEPRECIATION>                                 140,761
<TOTAL-ASSETS>                               1,489,847
<CURRENT-LIABILITIES>                          368,595
<BONDS>                                        413,248<F2>
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           417
<OTHER-SE>                                     671,644<F3>
<TOTAL-LIABILITY-AND-EQUITY>                 1,489,847
<SALES>                                        745,902
<TOTAL-REVENUES>                               924,271
<CGS>                                          328,444
<TOTAL-COSTS>                                  328,444
<OTHER-EXPENSES>                               753,253<F4>
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              30,212
<INCOME-PRETAX>                              (445,387)
<INCOME-TAX>                                    19,887
<INCOME-CONTINUING>                          (465,274)
<DISCONTINUED>                                (47,189)
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                 (512,463)
<EPS-PRIMARY>                                   (3.15)<F5>
<EPS-DILUTED>                                   (3.15)<F6>
<FN>
<F1>CONSISTS OF BOTH SHORT-TERM AND NONCURRENT 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, WRITE-OFF OF PURCHASED IN-PROCESS
TECHNOLOGIES, COSTS RELATED TO NOVARTIS TRANSACTION, RESTRUCTURING AND
REORGANIZATION CHARGES AND OTHER OPERATING EXPENSES.
<F5>REPRESENTS BASIC NET LOSS PER SHARE. BASIC LOSS PER SHARE FROM CONTINUING
OPERATIONS AND BASIC LOSS PER SHARE FROM DISCONTINUED OPERATIONS WERE ($2.86)
AND ($0.29), RESPECTIVELY.
<F6>REPRESENTS DILUTED NET LOSS PER SHARE. DILUTED LOSS PER SHARE FROM CONTINUING
OPERATIONS AND DILUTED LOSS PER SHARE FROM DISCONTINUED OPERATIONS WERE ($2.86)
AND ($0.29), RESPECTIVELY.
</FN>
        

</TABLE>