<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS FINANCIAL INFORMATION EXTRACTED FROM CHIRON CORPORATION'S
UNAUDITED CONSOLIDATED BALANCE SHEET DATED MARCH 31, 2000 AND UNAUDITED
CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS FOR THE THREE MONTHS ENDED MARCH
31, 2000 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000

                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-2000
<PERIOD-START>                             JAN-01-2000
<PERIOD-END>                               MAR-31-2000
<CASH>                                         380,326
<SECURITIES>                                 1,035,288<F1>
<RECEIVABLES>                                  235,602<F5>
<ALLOWANCES>                                    15,569
<INVENTORY>                                     92,368
<CURRENT-ASSETS>                             1,483,850
<PP&E>                                         528,856
<DEPRECIATION>                                 229,947
<TOTAL-ASSETS>                               2,404,039
<CURRENT-LIABILITIES>                          563,120
<BONDS>                                         93,062<F2>
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         1,819
<OTHER-SE>                                   1,692,885<F3>
<TOTAL-LIABILITY-AND-EQUITY>                 2,404,039
<SALES>                                        157,606
<TOTAL-REVENUES>                               216,745
<CGS>                                           51,251
<TOTAL-COSTS>                                   51,251
<OTHER-EXPENSES>                                75,441<F4>
<LOSS-PROVISION>                                 2,019
<INTEREST-EXPENSE>                               5,026
<INCOME-PRETAX>                                 58,161
<INCOME-TAX>                                    18,077
<INCOME-CONTINUING>                             40,084
<DISCONTINUED>                                     152
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    40,236
<EPS-BASIC>                                       0.22
<EPS-DILUTED>                                     0.21
<FN>
<F1>CONSISTS OF SHORT-TERM AND NONCURRENT INVESTMENTS IN MARKETABLE DEBT AND
EQUITY SECURITIES.
<F2>CONSISTS OF CONVERTIBLE SUBORDINATED DEBENTURES AND NOTES PAYABLE, NET OF
CURRENT MATURITIES.
<F3>CONSISTS OF ADDITIONAL PAID-IN CAPITAL, ACCUMULATED DEFICIT, COST OF
TREASURY STOCK AND ACCUMULATED OTHER COMPREHENSIVE INCOME.
<F4>CONSISTS OF RESEARCH AND DEVELOPMENT, RESTRUCTURING AND REORGANIZATION
CHARGES AND OTHER OPERATING EXPENSES.
<F5>CONSISTS OF ACCOUNTS RECEIVABLE AND CURRENT AND NONCURRENT PORTIONS OF NOTES
RECEIVABLE.
</FN>