Exhibit 32.1

Certification
Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
(Subsections (a) and (b) of Section 1350,
Chapter 63 of Title 18, United States Code)

Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of Section 1350, Chapter 63 of Title 18, United States Code), each of the undersigned officers of Vertex Pharmaceuticals Incorporated, a Massachusetts corporation (the “Company”), does hereby certify, to such officer’s knowledge, that the Quarterly Report on Form 10-Q for the quarter ended March 31, 2006 (the “Form 10-Q”) of the Company fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and the information contained in the Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of the Company.

Dated: May 10, 2006	/s/ JOSHUA S. BOGER
	Joshua S. Boger
	Chairman, President and Chief Executive Officer
	(principal executive officer)
Dated: May 10, 2006	/s/ IAN F. SMITH
	Ian F. Smith
	Executive Vice President and Chief Financial Officer
	(principal financial officer)

1