comScore (SCOR) 10-Q 2014 Q3 Quarterly report

Exhibit 32.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the quarterly report of comScore, Inc. (the “Company”) on Form 10-Q for the period ending September 30, 2014 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Serge Matta, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that to 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/ SERGE MATTA

Serge Matta

President and Chief Executive Officer

October 29, 2014