Exhibit 13.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADDED BY

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report of Tsakos Energy Navigation Limited (the “Company”) on Form 20-F for the period ending December 28, 2003 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Nikolas P. Tsakos, President and Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as added by § 906 of the Sarbanes-Oxley Act of 2002, that, based on my knowledge:

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

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

/s/ Nikolas P. Tsakos

Nikolas P. Tsakos

President and Chief Executive Officer

June 29, 2004