News Release CACI International Inc · 1100 North Glebe Road · Arlington Virginia 22201

CACI Appoints Ronald Cournoyer as Senior Vice President for Homeland Security

Arlington, VA, May 9, 2005 — CACI International Inc (NYSE:CAI) announced today that it has appointed Ronald Cournoyer as Senior Vice President for Homeland Security. In this role, Mr. Cournoyer will serve as CACI's single point of contact for company-wide initiatives addressing programs and opportunities in this market. Formerly in the company's managed network services area, Mr. Cournoyer offers nearly 35 years of experience in the federal market, with a strong background in leadership positions supporting programs for the Department of Defense and law enforcement agencies of the federal government.

Homeland security is a key element of CACI's strategic growth plans, and the company has positioned a broad range of offerings for this market. CACI provides intelligence services and knowledge management to help collect and organize data, telecommunications for sharing this data across high-speed networks, and information assurance for data protection. CACI also offers engineering solutions for designing, developing, and prototyping data collection and analysis systems that can be used by warfighters, border patrols, law enforcement agents, and a wide range of national security stakeholders.

Mr. Cournoyer's prior responsibility was leading CACI's managed network services business development efforts to government agencies and commercial clients. His background includes executive and technical positions with BDM and TRW, where he was responsible for more than $300 million in federal contracts. In his 24-year Air Force career, Mr. Cournoyer held executive positions that included Director of the Federal Systems Integration and Management Center and Director of the White House Communications Agency. For the latter, he managed 800 personnel and a $100 million budget supporting the President, Vice President, National Security Council, and the White House staff. Mr. Cournoyer also holds a current Top Secret clearance.

"CACI has an enterprise-wide vision for pursuing business opportunities in homeland security," Mr. Cournoyer said. "From across all our business groups and capabilities, we provide comprehensive solutions that are an excellent fit with the Department of Homeland Security and Department of Defense, state and local agencies, the intelligence community, and the international arena."

According to CACI Chairman, President, and CEO Dr. J.P. (Jack) London, "Ron Cournoyer brings top-quality leadership to CACI's homeland security team. Our clients will benefit from his dedicated focus and the exceptional expertise he brings in matching CACI solutions to homeland security requirements. Ron also has developed a very sound strategic view, a blueprint to go forward, and a strategic plan to leverage CACI capabilities to maximize our clients' success in securing and protecting our nation."

CACI International Inc provides the IT and network solutions needed to prevail in today's new era of defense, intelligence, and e-government. From systems integration and managed network solutions to knowledge management, engineering, simulation, and information assurance, we deliver the IT applications and infrastructures our federal customers use to improve communications and collaboration, secure the integrity of information systems and networks, enhance data collection and analysis, and increase efficiency and mission effectiveness. Our solutions lead the transformation of defense and intelligence, assure homeland security, enhance decision-making, and help government to work smarter, faster, and more responsively. CACI, a member of the Russell 2000 and S&P SmallCap 600 indices, provides dynamic careers for approximately 9,500 employees working in over 100 offices in the U.S. and Europe. CACI is the IT provider for a networked world. Visit CACI on the web at www.caci.com.

There are statements made herein which do not address historical facts and, therefore could be interpreted to be forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. Such statements are subject to factors that could cause actual results to differ materially from anticipated results. The factors that could cause actual results to differ materially from those anticipated include, but are not limited to, the following: regional and national economic conditions in the United States and the United Kingdom, including conditions that result from terrorist activities or war; failure to achieve contract awards in connection with recompetes for present business and/or competition for new business; the risks and uncertainties associated with client interest in and purchases of new products and/or services; continued funding of U.S. government or other public sector projects in the event of a priority need for funds, such as homeland security, the war on terrorism or rebuilding Iraq; government contract procurement (such as bid protest, small business set asides, etc.) and termination risks; the results of government investigations into allegations of improper actions related to the provision of services in support of U.S. military operations in Iraq; the results of the appeal of CACI International Inc ASBCA No. 53058; individual business decisions of our clients; paradigm shifts in technology; competitive factors such as pricing pressures and/or competition to hire and retain employees (particularly those with security clearances); material changes in laws or regulations applicable to our businesses, particularly in connection with (i) government contracts for services, (ii) outsourcing of activities that have been performed by the government, and (iii) competition for task orders under Government Wide Acquisition Contracts ("GWACs") and/or schedule contracts with the General Services Administration; our own ability to achieve the objectives of near term or long range business plans; and other risks described in the company's Securities and Exchange Commission filings.

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