ArcSight Announces Annual Stockholders Meeting to Be Held on Thursday, September 25, 2008

Cupertino, Calif. – July 23, 2008 – ArcSight, Inc. (Nasdaq: ARST), a leading global provider of compliance and security management solutions that protect enterprises and government agencies, today announced the company’s 2008 annual meeting of stockholders will be held on Thursday, September 25, 2008, at 10:00 a.m. Pacific Time. The meeting will be held at the company’s headquarters located at 5 Results Way, Cupertino, California 95014. The record date for the annual meeting is August 15, 2008, and only stockholders of record on that date are eligible to attend and vote at the meeting. ArcSight intends to begin mailing the proxy statements for the annual meeting to stockholders on or about August 25, 2008.

About ArcSight
ArcSight (NASDAQ: ARST) is a leading global provider of compliance and security management solutions that protect enterprises and government agencies. ArcSight helps customers comply with corporate and regulatory policy, safeguard their assets and processes, and control risk. The ArcSight platform collects and correlates user activity and event data across the enterprise so that businesses can rapidly identify, prioritize, and respond to compliance violations, policy breaches, cybersecurity attacks, and insider threats. For more information, visit www.arcsight.com.

ArcSight, ArcSight Logger and the ArcSight logo are trademarks of ArcSight, Inc.

Contact Information:
Robert Dougherty
415-293-4427
IR@arcsight.com
Robert.dougherty@fdashtonpartners.com