================================================================================

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                    FORM 8-K


                                 CURRENT REPORT

     Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934


                         Date of Report: April 20, 2006


                             UnionBanCal Corporation
             (Exact name of registrant as specified in its charter)


        Delaware                      001-15081                  94-1234979
(State of Incorporation)      (Commission File Number)          (IRS Employer
                                                             Identification No.)


                              400 California Street
                          San Francisco, CA 94104-1302
                               Tel. (415) 765-2969


Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2. below):

[ ] Written communications pursuant to Rule 425 under the Securities Act (17
    CFR 230.425)

[ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17
    CFR 240.14a-12)

[ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the
    Exchange Act (17 CFR 240.14d-2(b))

[ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the
    Exchange Act (17 CFR 240.13e-4(c))

================================================================================




Item 2.02 Results of Operations and Financial Condition.

     On April 20, 2006, the Company issued a press release concerning earnings
for the first quarter of 2006, a copy of which is furnished herewith as Exhibit
99.1.


Item 9.01 Financial Statements and Exhibits

     (c)  Exhibits:


  Exhibit No.             Description
- --------------------------------------------------------------------------------
     99.1                 Press release dated April 20, 2006.




                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.


Dated: April 20, 2006


                                                    UNIONBANCAL CORPORATION


                                                    By:  /S/ DAVID I. MATSON
                                                       -------------------------
                                                            David I. Matson
                                                        Chief Financial Officer
                                                       (Duly Authorized Officer)




                                  EXHIBIT INDEX

  Exhibit No.             Description
- --------------------------------------------------------------------------------
     99.1                 Press release dated April 20, 2006.