Quest Diagnostics Incorporated , the nation's leading provider of diagnostic testing, information and services, today announced that its Board of Directors declared a quarterly cash dividend on Quest Diagnostics common stock of $0.10 per share, payable on October 18, 2006, to shareholders of record on October 4, 2006.

About Quest Diagnostics

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: http://www.questdiagnostics.com/.

The statements in this press release which are not historical facts or information may be forward-looking statements. These forward-looking statements involve risks and uncertainties that could cause actual results and outcomes to be materially different. Certain of these risks and uncertainties may include, but are not limited to, competitive environment, changes in government regulations, changing relationships with customers, payers, suppliers and strategic partners and other factors described in the Quest Diagnostics Incorporated 2005 Form 10-K and subsequent SEC filings.

SOURCE: Quest Diagnostics Incorporated

CONTACT: Investors: Laure Park, +1-201-393-5030, or Media: Jennifer
Somers, +1-201-393-5700, both of Quest Diagnostics

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