EXHIBIT 5

[LETTERHEAD OF DAVIS POLK & WARDWELL]

March 19, 2007

CVS Corporation

One CVS Drive

Woonsocket, RI 02895

Ladies and Gentlemen:

We are acting as counsel for CVS Corporation (the “Registrant”) in connection with its Registration Statement on Form S-8 (the “Registration Statement”) being filed by the Registrant under the Securities Act of 1933, as amended (the “1933 Act”), relating to the authorization of the issuance of an aggregate of 33,246,843 shares of common stock (the “Shares”) pursuant to awards under the following plans: the Caremark Rx, Inc. 2004 Incentive Stock Plan, the Caremark Rx, Inc. 1992 Stock Incentive Plan, as amended, the Amended and Restated Caremark Rx, Inc. 1995 Stock Option Plan, the Caremark Rx, Inc. Amended and Restated 1997 Long Term Incentive Compensation Plan, as amended, the Caremark Rx, Inc. 1998 New Employee Stock Option Plan, as amended, the Caremark Rx, Inc. 1998 Stock Option Plan, as amended, the Advance Paradigm, Inc. Amended and Restated 1997 Nonstatutory Stock Option Plan, as amended, and the Advance Paradigm, Inc. Amended and Restated Incentive Stock Option Plan, as amended (collectively, the “Plans”).

We have examined originals or copies, certified or otherwise identified to our satisfaction, of such documents, corporate records, certificates of public officials and other instruments relating to the issuance of the Shares as we have deemed necessary for the purpose of this opinion.

Upon the basis of the foregoing, we are of the opinion that the Shares deliverable pursuant to the Plans have been duly authorized and, when and to the extent issued pursuant to the terms of the Plans, will be validly issued, fully paid and nonassessable.

We hereby consent to the filing of this opinion as Exhibit 5 to the Registration Statement.

    Very truly yours,

    /s/ Davis Polk and Wardwell