POWER OF ATTORNEY



Know all by these presents, that the undersigned hereby constitutes and

appoints each of Gerald J. Pappert, Todd C. Longsworth, Carolyn S. Iosca

and Susan Z.Fitzpatrick,and each of them acting alone, signing singly,

the undersigned's true and lawful attorney-in-fact to:

(1) execute for and on behalf of the undersigned, in the undersigned's

capacity as an officer, director and/or 10% or more stockholder of

Cephalon, Inc. (the "Company"), Forms 3, 4 and 5 (and any amendments thereto)

in accordance with Section 16(a) of the Securities Exchange Act of 1934,

as amended (the "1934 Act"), and the rules promulgated thereunder;

(2) do and perform any and all acts for and on behalf of the undersigned

which may be necessary or desirable to complete and execute any such

Form 3, 4 and 5 (and any amendments thereto) and to file timely such form

with the United States Securities and Exchange Commission and any

stock exchange or similar authority; and

(3) take any other action of any type whatsoever in connection with

the foregoing which in the opinion of such attorney-in-fact,

may be of benefit to, in the best interest of, or legally required by,

the undersigned, it being understood that the documents executed by such

attorney-in-fact on behalf of the undersigned pursuant to this

Power of Attorney shall be in such form and shall contain such terms

and conditions as such attorney-in-fact may approve in such

attorney-in-fact's discretion.



The undersigned hereby grants to each such attorney-in-fact full power

and authority to do and perform any and every act and thing whatsoever

requisite, necessary or proper to be done in the exercise of any of the

rights and powers herein granted, as fully to all intents and purposes

as the undersigned might or could do if personally present, with full

power of substitution or revocation, hereby ratifying and confirming

all that such attorney-in-fact, or such attorney-in-fact's substitute

or substitutes, shall lawfully do or cause to be done by virtue of

this power of attorney and the rights and powers herein granted.

The undersigned acknowledges that the foregoing attorneys-in-fact, in

serving in such capacity at the request of the undersigned,

are not assuming, nor is the Company assuming, any of the undersigned's

responsibilities to comply with Section 16 and or the 1934 Act.



This Power of Attorney shall remain in full force and effect until

the undersigned is no longer required to file Forms 3, 4 and 5 with

respect to the undersigned's holdings of and transactions in securities

issued by the Company, unless earlier revoked by the undersigned in a

signed writing delivered to each of the foregoing attorneys-in-fact.



IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney

to be executed as of this 28th day of January 2010.





 /s/ Wilco Groenhuysen

 Wilco Groenhuysen