OPINION RE: LEGALITY; CONSENT OF COUNSEL

[LETTERHEAD OF SIDLEY AUSTIN BROWN & WOOD LLP]

EXHIBIT (5) & (23)


February 8, 2002



Merrill Lynch & Co., Inc.
4 World Financial Center
New York, New York 10080

Gentlemen:

As your counsel, we have examined a copy of the Restated Certificate of
Incorporation, as amended, of Merrill Lynch & Co., Inc. (hereinafter called the
"Company"), certified by the Secretary of State of the State of Delaware. We are
familiar with the corporate proceedings had in connection with the proposed
issuance and sale by the Company to the Underwriter named in the Terms Agreement
referred to below, pursuant to an Underwriting Agreement dated August 5, 1998
(the "Underwriting Agreement"), between the Company and Merrill Lynch & Co.,
Merrill Lynch, Pierce, Fenner & Smith Incorporated ("MLPF&S"), as supplemented
by the Terms Agreement dated February 4, 2002 (the "Terms Agreement") between
the Company and MLPF&S (the "Underwriter"), of the Company's Strategic Return
Notes/SM/ Linked to the Biotech-Pharmaceutical Index due February 8, 2007 (the
"Notes") in an amount equal to $90,000,000 which equals the aggregate original
public offering price of the Notes. We have




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also examined a copy of the Indenture between the Company and JPMorgan Chase
Bank as Trustee, dated as of April 1, 1983, as amended (the "Indenture"), and
the Company's Registration Statement on Form S-3 (File No. 333-52822) relating
to the Notes (the "Registration Statement"). Based upon the foregoing and upon
such further investigation as we deemed relevant in the premises, we are of the
opinion that:

1. The Company has been duly incorporated under the laws of the State
of Delaware.

2. The Notes have been duly and validly authorized by the Company and
when the Notes have been duly executed and authenticated in accordance with the
terms of the Indenture and delivered against payment therefor as set forth in
the Underwriting Agreement, as supplemented by the Terms Agreement, the Notes
will constitute valid and legally binding obligations of the Company,
enforceable against the Company in accordance with their terms, except to the
extent that enforcement thereof may be limited by bankruptcy, moratorium,
insolvency, reorganization or similar laws relating to or affecting creditors'
rights generally and except as enforcement thereof is subject to general
principles at equity (regardless of whether enforcement is considered in a
proceeding in equity or at law).

We consent to the filing of this opinion as an exhibit to the
Registration Statement and as an exhibit to the Current Report of the Company on
Form 8-K dated February 8, 2002.



Very truly yours,

/s/ Sidley Austin Brown & Wood LLP




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