Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statements on Forms S-3 (No. 333-138586, 333-131233, 333-129905, and 333-140076) and S-8 (No. 333-127450, 333-116151, and 333-148114) of Alnylam Pharmaceuticals, Inc. of our report dated March 7, 2008 relating to the financial statements and the effectiveness of internal control over financial reporting, which appears in this Form 10-K.

/s/ PricewaterhouseCoopers LLP
Boston, MA
March 7, 2008