Quest Diagnostics Incorporated , the nation's leading provider of diagnostic testing, information and services, announced that it is scheduled to speak at the Merrill Lynch Health Services Investor Conference at the Merrill Lynch Headquarters in New York City on Tuesday, November 27, 2007. The Quest Diagnostics presentation is scheduled to begin at 10:15 a.m. Eastern Time.

During the conference, the company will reiterate its 2007 guidance for revenues of between $6.6 billion and $6.7 billion, operating income of approximately 16% of revenues, and earnings per diluted share from continuing operations of between $2.84 and $2.91 These estimates exclude $0.04 per share in total first quarter charges associated with workforce reductions and the expense of in-process research and development, and are before potential additional special charges.

The presentation will be webcast live during the conference and will be available to registered investors on the following site: http://www.veracast.com/webcasts/ml/healthservices07/54104126.cfm and to the public on http://www.questdiagnostics.com/. In addition, the archived webcast will be available within 24 hours after the presentation and will remain available until December 12, 2007.

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.

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 2006 Form 10-K and subsequent SEC filings.

Web site: http://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