PRESS RELEASE DETAIL


Nov 10, 2008

CoStar Group to Announce Financial Results for Third Quarter 2008 On October 29, 2008

2008-10-07 2008 CoStar Group to Announce Financial Results for Third Quarter 2008 On October 29, 2008 Quarterly Earnings Report to be Issued After Market Close On Wedn...

2008-10-07 2008 CoStar Group to Announce Financial Results for Third Quarter 2008 On October 29, 2008 Quarterly Earnings Report to be Issued After Market Close On Wednesday, October 29; Conference Call to Discuss Financial Results Scheduled for 11:00 AM EDT On Thursday, October 30

BETHESDA, Md., Oct. 7, 2008 -- CoStar Group, Inc. (Nasdaq: CSGP ), the number one provider of information/marketing services to the commercial real estate industry, will announce its third quarter 2008 financial results following the market close on Wednesday, October 29, 2008. Management will hold an investor conference call to discuss the quarterly results and the company's outlook for the fourth quarter at 11:00 AM EDT on Thursday, October 30th.

To participate in the conference call, please dial (800) 230-1074 (from the United States and Canada) or (612) 234-9960 (from all other countries) and enter conference reservation code 964778. Investors may also listen to an audio web cast of this conference call by accessing the link in the Investors section of CoStar's web site at www.CoStar.com.

An audio recording of the conference will be available for replay approximately one hour after the call's completion and remain available through midnight on November 13, 2008. To access the recorded call, please dial (800) 475-6701 (from the U.S. and Canada) or (320) 365-3844 (from all other countries) using access code 964778. The webcast replay will also be available in the Investors section of CoStar Group's web site for a period of time following the call.

About CoStar Group, Inc.

CoStar Group, Inc. (Nasdaq: CSGP ) is the number one provider of information/marketing 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, CoStar has approximately 1,300 people working for the company worldwide, including the largest professional research organization in the industry. For more information, visit http://www.costar.com.

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, 2007 and CoStar's Form 10-Q for the quarter ended June 30, 2008, 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.

'