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                             AUDIT COMMITTEE CHARTER
                             (Approved May 26, 2000)

The Board of Directors of Chiron Corporation (the "Board"), upon
recommendation of the Audit Committee of the Board, has adopted this Audit
Committee Charter to define certain of the functions, responsibilities and
authorities of the Audit Committee of the Board.

The Board shall appoint three of its members to serve as the Audit Committee.
Its membership shall comply with applicable law and regulatory standards and
shall include persons knowledgeable in financial and accounting matters and
one or more persons having a background in accounting or related financial
management. Each member of the Committee shall be free of any relationship
that, in the opinion of the Board, would interfere with his or her
independent exercise of appropriate judgment and shall be independent of
management of the Company, provided, however, that the Board may determine
that it is in the best interests of the Company and its stockholders that not
more than one member of the Audit Committee may be appointed who is not
independent of management within the meaning of the standards of independence
established by the Securities and Exchange Commission and the listing
requirement of the NASDAQ National Market System.  Notwithstanding the
foregoing, currently serving employees or officers of the Company, or their
immediate family members,  shall not serve as members of the Audit Committee.

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The Audit Committee is a standing committee of the Board, whose primary
function is to assist the Board in fulfilling the Board's general oversight
responsibilities with respect to (i) the quality and integrity of financial
information provided to stockholders and others; and (ii) the quality and
integrity of the Company's system of internal controls.

Specifically, the Audit Committee shall have the following functions:

-     The Committee shall provide the primary oversight on behalf of the Board
      of the selection, engagement, performance and termination of the
      independent auditors for the annual audit of the Company's financial
      statements. The Committee shall review the independence of the
      independent auditors, including consideration of their annual written
      affirmation of independence, review of any other material engagements
      with the Company or its subsidiaries, and such other matters as the
      Committee may determine to be appropriate.

-     The Committee shall review with the independent auditors and management
      the nature and proposed scope of the annual audit.

-     The Committee shall review with management and the independent auditors
      the financial statements (including quarterly reports) of the Company.
      The Committee will review, prior to release or filing with the Securities
      and Exchange Commission, the annual consolidated financial statements of
      the Company. Review of quarterly financial statements and related reports
      need not precede the public release or filing of such

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      statements by the Company. It is anticipated that these reviews will
      include discussion of the quality of earnings, reviews of reserves and
      accruals, consideration of the suitability of accounting principles,
      reviews of the judgmental areas and audit adjustments, whether or not
      recorded.

-     The Committee shall receive and discuss with management and the
      independent auditors the reports required to be delivered to the Audit
      Committee on behalf of the Board  pursuant to applicable auditing
      standards.

-     The Committee shall oversee Chiron's internal audit function. The
      Committee shall review the audit plans and results of the internal audit
      function as they relate to the Committee's areas of responsibility.  The
      internal auditor shall have direct access to the Committee.  The internal
      auditor, however, shall be subject to the administration and supervision
      of the Chief Financial Officer or other member of management and may
      perform such other duties and responsibilities as management shall
      determine. Consequently, the internal auditor is not expected to be
      independent of management.

-     The Committee shall assess on behalf of the Board the quality and
      adequacy of Chiron's internal control environment and shall receive
      reports from the independent auditors and internal auditors regarding
      control matters. The Committee shall oversee the follow-up by management
      of any material control weakness reported by independent auditors or
      internal auditors or otherwise identified by the Committee.

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-     The Audit Committee may receive periodic reports and may discuss with
      management the status of material contingent liabilities, including, as
      appropriate, litigation, taxation matters, environmental or other areas
      of risk exposure as they relate to the areas of responsibility of the
      Committee, including review of financial statements disclosure and the
      quality of the control environment and otherwise as the Committee may
      determine in its discretion.

-     The Committee shall assess and discuss with management the quality and
      adequacy Chiron's internal legal compliance programs. The Committee shall
      review reports from the Chief Compliance Officer with respect to matters
      within the Committee's areas of responsibility. The Chief Compliance
      Officer shall have direct access to the Committee. However, as the Chief
      Compliance Officer performs other functions within the Company, he or she
      is not expected to be independent of management.

-     The Committee shall report to the Board periodically on activities within
      its areas of responsibility and shall review periodically its function
      under this Charter and provide recommendations to revise its
      responsibility or authority under this Charter for consideration by the
      Board.

      The Audit Committee is expected to establish and maintain free and open
      communication with the Company's independent auditors, the internal
      auditors, and management of the Company.  The Committee shall be
      available to meet periodically and upon request in

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      private executive sessions with representatives of independent auditors
      and the internal auditors.

      In discharging its oversight role, the Audit Committee is authorized to
      investigate any activity of the Company within its area of responsibility
      and to retain and direct the Company to pay the costs of such external
      advisers, including legal counsel or other experts, as the Committee may
      deem appropriate for this purpose.

      All officers and employees of the Company and its consolidated
      subsidiaries are directed to cooperate fully with and provide all
      information requested by the Committee. The Committee is entitled to rely
      upon factual reports, advice and recommendations provided by
      representatives of management, employees of the Company and its
      subsidiaries and expert advisors, to the fullest extent that the Board is
      so entitled under applicable law.

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