CoStar Group to Report Financial Results for Fourth Quarter and Full-Year 2007

Earnings Report to be Issued After Market Close On Wednesday, February 20; Conference Call to Discuss 2007 Financial Results and the Company's Outlook for 2008 Scheduled for Thursday, February 21


BETHESDA, Md., Jan. 30, 2008 (PRIME NEWSWIRE) -- CoStar Group, Inc. (Nasdaq:CSGP), the number one provider of information services to the commercial real estate industry, will report financial results for the fourth quarter and year ended December 31, 2007 after the market close on Wednesday, February 20, 2008. Management will conduct a conference call the following day, Thursday, February 21, 2008, at 11:00 a.m. Eastern Standard Time, to discuss the year-end financial results and the company's outlook for 2008.

To participate in the conference call, dial 888-688-0419 from within the United States, or 706-634-0964 from outside the United States. Investors may also access a live audio web cast of this conference call by accessing the link on the investors section of CoStar Group's web site at www.costar.com.

An audio recording of the conference will be available for replay two hours after the call's completion and remain available through midnight on March 6, 2008. The replay will also be available over the Internet at http://www.costar.com/corporate/investor/ for a period of time following the call. To access the recording, use the dial-in numbers and enter the Conference ID number listed below.

About CoStar Group, Inc.

CoStar Group, Inc. (Nasdaq:CSGP) is the number one provider of information services to commercial real estate professionals in the United States as well as the United Kingdom. CoStar's suite of services offers customers access via the Internet to the most comprehensive database of commercial real estate information throughout the U.S. as well as in the United Kingdom and France. Headquartered in Bethesda, MD, the company has approximately 1,300 employees, including the largest professional research organization in the industry. For more information, visit www.costar.com.



                       PRESS RELEASE ANNOUNCING
                   YEAR-END 2007 FINANCIAL RESULTS:
        After the market close on Wednesday, February 20, 2008

                           CONFERENCE CALL:
                     Thursday, February 21, 2008
                    11:00 a.m. - 12:00 Noon (EST)
         Hosted by CoStar Group President & Chief Executive Officer
      Andrew C. Florance and Chief Financial Officer Brian J. Radecki.

                 U.S. Dial-In Number:  (888) 688-0419
            International Dial-In Number:  (706) 634-0964
                       Conference ID:  33444915

                  Live web broadcast can be found at:
                  www.costar.com/corporate/investor/

                       CONFERENCE CALL REPLAY:
                 U.S. Dial-In Number:  (800) 642-1687
              International Dial-In Number:  (706) 645-9291
                       Conference ID:  33444915

This news release includes "forward-looking statements" including, without limitation, statements regarding CoStar's expectations, beliefs, intentions or strategies regarding the future. These statements are subject to many risks and uncertainties that could cause actual results to differ materially from these statements. More information about potential factors that could cause actual results to differ materially from those discussed in the forward-looking statements include, but are not limited to, those stated in CoStar's filings from time to time with the Securities and Exchange Commission, including CoStar's Form 10-K for the year ended December 31, 2006, under the heading "Risk Factors" and CoStar Group's Form 10-Q for the quarter ended September 30, 2007, under the heading "Risk Factors." All forward-looking statements are based on information available to CoStar on the date hereof, and CoStar assumes no obligation to update such statements.



            

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