Exhibit 32.1

Neurogen Corporation

Certification Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

(18 U.S.C. Section 1350)

Pursuant to the requirements of Section 906 of the Sarbanes-Oxley Act of 2002 (18 U.S.C. Sections 1350(a) and (b)), the undersigned hereby certifies as follows:

1. I am the President and Chief Executive Officer of Neurogen Corporation (the “Company”).

2. To the best of my knowledge:

a.   The Company's Quarterly Report on Form 10-Q for the period ended March 31, 2007 accompanying this Certification, in the form filed with the Securities and Exchange Commission (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 (the “Exchange Act”); and

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

By:	/s/ William H. Koster
	William H. Koster
	President and Chief Executive Officer
	Date: May 10, 2007