EXHIBIT (5) & (23)


May 5, 2005



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

Ladies and 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
December 3, 2004 (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 May 2, 2005 (the
"Terms Agreement") between the Company and MLPF&S (the "Underwriter"), of the
Company's PROtected Covered Call EnhancED Income NoteSSM Linked to the Income
Select 10 PROCEEDS Index due May 12, 2010 (the "Securities") in an amount equal
to $21,878,000 aggregate principal amount of the Securities. We have also
examined a copy of the Indenture between the Company and JPMorgan Chase Bank,
N.A. as Trustee, dated as of April 1, 1983, as amended (the "Indenture"), and
the Company's Registration Statement on Form S-3 (File No. 333-122639) relating
to the Securities (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 Securities have been duly and validly authorized by the
Company and when the Securities 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 Securities 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 May 5, 2005. We also consent to the use of our name under the caption
"United States Federal Income Taxation" in the prospectus supplement related to
the offering of the Securities.

Very truly yours,


/s/ Sidley Austin Brown & Wood LLP