London, UK – 29th February 2008 – ArcSight, Inc., (Nasdaq: ARST) today announced that it will issue a press release reporting financial results for the third quarter that ended January 31, 2008, after the close of the market on March 13, 2008.

ArcSight will host a conference call and live webcast at 2:00 p.m. Pacific Standard Time on March 13, 2008. To access the conference call, callers in the U.S. or Canada dial 800-218-4007 and international callers dial 303-262-2139. The webcast will be available live on the Investor Relations section of the company’s website at www.arcsight.com. An audio replay of the call will also be available to investors by phone beginning at approximately 4:00 p.m. Pacific Standard Time on March 13, 2008, until 11:59 p.m. Pacific Standard Time on March 20, 2008, by dialing 800-405-2236 from the U.S. or Canada or 303-590-3000 from all other countries, and entering passcode 11109896#. In addition, an archived webcast will be available on the Investor Relations section of the company’s website at www.arcsight.com.