Exhibit 5.1





















                 [LETTERHEAD OF WACHTELL, LIPTON, ROSEN & KATZ]


                                 August 10, 1999


Bank United Corp.
3200 Southwest Freeway
Suite 2600
Houston, Texas 77027

Ladies and Gentlemen:

          Reference is made to the Registration Statements on Form S-3 (File
Nos. 333-75937 and 333-83797), as amended, filed with the Securities and
Exchange Commission (the "Registration Statement") in connection with the
registration under the Securities Act of 1933, as amended (the "Securities Act")
of up to $830,000,000 of Preferred Stock, Class A Common Stock, Depositary
Shares, Junior Subordinated Debt Securities, Guarantee, Stock Purchase Contracts
and Stock Purchase Units of Bank United Corp. (the "Company"), and Trust
Preferred Securities of Bank United Capital Trust (the foregoing securities
being collectively referred to herein as the "Securities"). You have requested
our opinion with respect to the following matters.

          In connection with the delivery of this opinion, we have examined
originals or copies of the Restated Certificate of Incorporation and the By-Laws
of the Company, the Registration Statement and the exhibits thereto, certain
resolutions adopted or to be adopted by the Board of Directors, the form of
certificates representing the securities offered and such other records,
agreements, instruments, certificates and other documents of public officials,
the Company and its officers and representatives, and have made such inquiries
of the Company and its officers and representatives, as we have deemed necessary
or appropriate in connection with


Bank United Corp.
August 10, 1999
Page 2


the opinions set forth herein. We are familiar with the proceedings heretofore
taken, and with the additional proceedings proposed to be taken, by the Company
in connection with the authorization, registration, issuance and sale of the
Securities. With respect to certain factual matters, we have relied upon
representations from, or certificates of, officers of the Company. In making
such examination and rendering the opinions set forth below, we have assumed
without verification the genuineness of all signatures, the authenticity of all
documents submitted to us as originals, the authenticity of the originals of
such documents submitted to us as certified copies, the conformity to originals
of all documents submitted to us as copies, the authenticity of the originals of
such later documents, that all documents submitted to us as certified copies are
true and correct copies of such originals and the legal capacity of all
individuals executing such documents.

          Based on such examination and review, and subject to the foregoing, we
are of the opinion that, when any applicable state securities or Blue Sky laws
have been complied with, and upon issuance, delivery and payment therefor in the
manner contemplated by the Registration Statement, the Securities will be
validly issued, fully paid and non-assessable.

          We are members of the Bar of the State of New York, and we have not
considered, and we express no opinion as to, the laws of any jurisdiction other
than the laws of the United States of America, the State of New York and the
General Corporation Law of the State of Delaware.

          We consent to the inclusion of this opinion as an exhibit to the
Registration Statement and to the reference to our firm in the prospectus that
is a part of the Registration Statement, and in any supplements thereto. In
giving such consent, we do not hereby admit that we are in the category of
persons whose consent is required under Section 7 of the Securities Act.

                                     Very truly yours,



                                     /s/ Wachtell, Lipton, Rosen & Katz