Quest Diagnostics Incorporated , the nation's leading provider of diagnostic testing, information and services, announced today that it will make public its first-quarter 2008 results on Monday, April 21, before the market opens, and that it will conduct it's first quarter investor conference call at 8:30 a.m. ET on that day.

The public may access the conference call through a live audio webcast available on Quest Diagnostics' Investor Relations link on the Internet at www.questdiagnostics.com/investor.

The conference call can also be accessed by dialing 210-839-8500, passcode 3214469. The company suggests participants dial in approximately 10 minutes before the call. Please note that this feature will be in listen-only mode.

A replay of the call may be accessed through the Internet at www.questdiagnostics.com/investor or by dialing 866-431-7950, or 203-369-0981 for international callers. No access code will be required. Telephone replays will be available from 10:30 a.m. ET on April 21 until midnight ET on May 19, 2008.

Anyone listening to the Quest Diagnostics call is encouraged to read the company's 2007 Annual Report on form 10-K, on file with the Securities and Exchange Commission, including the discussion of risk factors and historical results of operations and financial condition.

Quest Diagnostics is the leading provider of diagnostic testing, information and services that patients and doctors need to make better healthcare decisions. The company offers the broadest access to diagnostic testing services through its national network of laboratories and patient service centers, and provides interpretive consultation through its extensive medical and scientific staff. Quest Diagnostics is a pioneer in developing innovative new diagnostic tests and advanced healthcare information technology solutions that help improve patient care. Additional company information is available at: www.questdiagnostics.com.

SOURCE: Quest Diagnostics Incorporated

CONTACT: Investors: Laure Park, +1-973-520-2900; or Media: Nancy
Fitzsimmons, +1-973-520-2800, both for Quest Diagnostics Incorporated

Web site: http://www.questdiagnostics.com/