East West Bancorp (EWBC) 10-Q 2003 Q1 Quarterly report

QuickLinks -- Click here to rapidly navigate through this document

Exhibit 99.1

CERTIFICATION

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

        In connection with the Quarterly Report of East West Bancorp, Inc. (the "Company") on Form 10-Q for the three month period ended March 31, 2003, as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Dominic Ng, President and Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. section 1350, as adopted pursuant to section 906 of the Sarbanes-Oxley Act of 2002, to the best of my knowledge that:

(a)

the Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and



(b)

the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: May 9, 2003
	/s/  DOMINIC NG      Dominic Ng President and Chief Executive Officer

        A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.

QuickLinks

CERTIFICATION