EXHIBIT 5.1
                         [BANK UNITED CORP. LETTERHEAD]

                                  June 16, 1999
Bank United Corp.
3200 Southwest Freeway
Suite 2600
Houston, Texas  77027

Ladies and Gentlemen:

I am General Counsel of Bank United Corp., a Delaware corporation (the
"Company"). The Company proposes to offer up to 710,000 shares of its Class A
Common Stock, par value $.01 per share (the "Common Stock"), to the shareholders
of Texas Central Bancshares, Inc. ("TCBI") in connection with the merger of BUC
Acquisition Corporation II, a wholly owned subsidiary of the Company ("Newco"),
with and into TCBI pursuant to the terms of an Agreement and Plan of
Reorganization dated as of March 23, 1999 by and among the Company, Newco, and
TCBI (the "Merger Agreement"). The Company has filed a Registration Statement on
Form S-4 ("Registration Statement") with the Securities and Exchange Commission
under the Securities Act of 1933, as amended, with respect to the Common Stock
to be issued pursuant to the Merger Agreement.

As General Counsel of the Company, I am familiar with the facts relating to this
opinion and have made such investigations of law as I have deemed necessary and
relevant as a basis hereof. I have assumed the genuineness of all signatures,
the authenticity of all documents, certificates and records submitted to me as
originals, the conformity to original documents, certificates and records of all
documents, certificates and records submitted to me as copies, and the
truthfulness of all statements of fact contained therein. Based on the
foregoing, and subject to the limitations set forth herein, and having due
regard for such legal considerations as I deem relevant, I am of the opinion
that, upon issuance pursuant to the terms of the Merger Agreement, the Common
Stock will be legally issued, fully paid and non-assessable. The foregoing
opinion is based on and is limited to the corporate laws of the State of
Delaware and the relevant laws of the United States of America, and I render no
opinion with respect to the laws of any other jurisdiction.

I hereby consent to the filing of this opinion with the Securities and Exchange
Commission as an exhibit to the Registration Statement and to the use of my name
therein.

                                    Very truly yours,

                                    BANK UNITED CORP.

                                    /s/ Jonathon K. Hefron
                                    Jonathon K. Heffron
                                    General Counsel