EX-99.906CERT1

CERTIFICATION PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Patrick  J.  Sheppard,  President  and Chief  Executive  Officer  and  Steven M.
Anderson,  Vice  President  and Treasurer of Mellon  Institutional  Funds Master
Portfolio (the "Registrant"), each certify to the best of their knowledge that:

1.The Registrant's periodic report on Form N-CSR for the year ended December 31,
2003 (the "Form N-CSR") fully complies with the requirements of section 15(d) of
the Securities Exchange Act of 1934, as amended; and

2.The information contained in the Form N-CSR fairly presents, in all material
respects, the financial condition and results of operations of the Registrant.

______________________________
Patrick J. Sheppard
President and Chief Executive Officer

Date: ____________ __, 2004

______________________________
Steven M. Anderson
Vice President and Treasurer

Date: ____________ __, 2004

This certification is being furnished to the Securities and Exchange  Commission
solely  pursuant to Rule 30a-2(b) under the  Investment  Company Act of 1940, as
amended, and 18 U.S.C. ss. 1350 and is not being filed as part of the Form N-CSR
with the Commission.