Investor Information

Common Stock
Quest Diagnostics Incorporated (ticker symbol: “DGX”) shares are listed on the New York Stock Exchange.

Quest Diagnostics is a component of several stock indices, including the S&P 500, Dow Jones Sustainability World Index and other social responsibility indices.

Annual Meeting
The annual meeting of shareholders will be held on Friday, May 16, 2008, at The Hilton at Short Hills, 41 John F. Kennedy Parkway, Short Hills, New Jersey, at 10:30 A.M. Eastern Time. A proxy statement and annual report were mailed to shareholders of record as of March 18, 2008.

Address all inquiries to:
Investor Relations Department Quest Diagnostics Incorporated 3 Giralda Farms Madison, NJ 07940 (973) 520-2900 E-mail: investor@questdiagnostics.com

Additional Information
Corporate news releases, our Annual Report, Proxy Statement, Forms 10-K and 10-Q and other information about the company, including locations of facilities, are available at Quest Diagnostics’ web site at: www.questdiagnostics.com/investor

Transfer Agent and Registrar
National City Bank acts as transfer agent and registrar and dividend paying agent, and maintains all shareholder records for the company. If you have questions about the shares of Quest Diagnostics you own, wish to report a change of address or lost stock certificates or dividend checks, or would like to enroll in the company’s automatic dividend reinvestment or direct deposit program, please contact National City Bank directly:

National City Bank
Shareholder Services
P.O. Box 92301
Cleveland, Ohio 44193-0900
Phone: (800) 622-6757
E-mail:
shareholder.inquiries@nationalcity.com

Corporate Headquarters
3 Giralda Farms
Madison, NJ 07940
(973) 520-2700

Corporate Governance
We are committed to strong corporate governance. We provide information regarding our corporate governance at www.questdiagnostics.com/ governance, where we post our Code of Business Ethics, Integrity Commitment, Values, Corporate Governance Guidelines, Certificate of Incorporation and Bylaws. We also post on this web page the charters for committees of our Board of Directors: Audit and Finance Committee; Compensation Committee; Executive Committee; Governance Committee; and Quality, Safety and Compliance Committee.

Senior Contacts
Inquiries to our senior management may be sent via e-mail to:
SeniorManagement@ questdiagnostics.com.
Inquiries to our Board of Directors may be sent via e-mail to:
LeadIndependentDirector@ questdiagnostics.com.

Inquiries to the company’s senior management or the Board of Directors may be sent via e-mail to:
seniormanagement@ questdiagnostics.com or
LeadIndependentDirector@
questdiagnostics.com

Trademarks
Quest Diagnostics, Quest and the Sun-Q logo are registered trademarks of Quest Diagnostics.

Care360, ClariSure, Enterix, HemoCue, HepaScore and Leumeta, are trademarks of Quest Diagnostics.

All other trademarks are the property of their respective owners.