On Assignment, Inc. Schedules Investor Conference Call December 21, 2006 at 10:30 A.M. ET

CALABASAS, Calif., Dec. 20 /PRNewswire-FirstCall/ -- On Assignment, Inc. announced today that it will hold a conference call on Thursday, December 21, 2006 at 10:30 a.m. ET to discuss its definitive agreement to acquire VISTA Staffing Solutions, a privately owned, leading provider of physician staffing, known as locum tenens, and permanent physician search services.

Interested parties are invited to listen to the conference call by dialing (877) 407-9039 or (201) 689-8470 ten minutes before the call. A replay of the conference call can be accessed from approximately 1:00 p.m. ET on Thursday December 21, 2006 through January 4, 2007 by dialing (877) 660-6853 or (201) 612-7415 with account number 3055 and conference ID# 224718.

This call is being webcast by Thomson/CCBN and can be accessed at On Assignment's web site at www.onassignment.com. Individual investors can also listen at Thomson/CCBN's site at www.fulldisclosure.com or by visiting any of the investor sites in Thomson/CCBN's Individual Investor Network. Institutional investors can access the call via Thomson/CCBN's password- protected event management site, StreetEvents at www.streetevents.com.

About On Assignment

On Assignment, Inc. is a diversified professional staffing firm providing flexible and permanent staffing solutions in specialty skills including Laboratory/Scientific, Healthcare, and Medical, Financial & Health Information Services. The corporate headquarters are located in Calabasas, California. On Assignment, Inc. was founded in 1985 as On Assignment/Lab Support and went public in 1992. The company's branch network encompasses approximately 60 branch offices across the United States, the United Kingdom, the Netherlands, and Belgium. On Assignment, Inc.'s common stock is traded on the Nasdaq Stock Market under the symbol ASGN.

About VISTA Staffing Solutions

VISTA Staffing Solutions (www.vistastaff.com) is a leading provider of temporary physician staffing and permanent physician search services. Founded in 1990, the employee-owned company helps hospitals, medical practices and government agencies solve their physician staffing challenges. VISTA is the only agency that offers short- and long-term domestic jobs, international work opportunities, and permanent placement for physicians. The company is a founding member of the National Association of Locum Tenens Organizations (NALTO).

Safe Harbor

Certain statements made in this news release are "forward-looking statements" within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended, and involve a high degree of risk and uncertainty. All statements in this release, other than those setting forth strictly historical information, are forward looking statements. Forward-looking statements are not guarantees of future performance, and actual results might differ materially. Factors that could cause or contribute to such differences include actual demand for our services, our ability to attract, train and retain qualified staffing consultants, our ability to remain competitive in obtaining and retaining temporary staffing clients, the availability of qualified temporary nurses and other qualified temporary professionals, management of our growth, continued performance of our enterprise-wide information systems, our ability to successfully make or integrate new acquisitions and other risks detailed from time to time in our reports filed with the Securities and Exchange Commission, including our Annual Report on Form 10-K for the year ended December 31, 2005, as filed with the SEC on March 16, 2006. We specifically disclaim any intention or duty to update any forward-looking statements contained in this news release.

(Logo: http://www.newscom.com/cgi-bin/prnh/20041022/LAF035LOGO) Contact: On Assignment, Inc. Peter Dameris Chief Executive Officer and President (818) 878-7900 Investors/Media: The Ruth Group Carol Ruth/Jason Rando (646) 536-7004/7025 cruth@theruthgroup.comjrando@theruthgroup.com

Photo: NewsCom: http://www.newscom.com/cgi-bin/prnh/20041022/LAF035LOGOAP Archive: http://photoarchive.ap.orgPRN Photo Desk, photodesk@prnewswire.comOn Assignment, Inc.

CONTACT: Peter Dameris, Chief Executive Officer and President of OnAssignment, Inc., +1-818-878-7900; or Investors/Media, Carol Ruth,+1-646-536-7004, cruth@theruthgroup.com, or Jason Rando, +1-646-536-7025,jrando@theruthgroup.com, both of The Ruth Group, for On Assignment, Inc.

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