ManTech Will Hold Conference Call to Discuss First Quarter 2005 Result

    Business Editors

    FAIRFAX, Va.--(BUSINESS WIRE)--April 6, 2005--Mantech International Corporation (Nasdaq:MANT):

    Call moved back a week so CEO can accept industry award

WHAT: Mantech International Corporation (Nasdaq:MANT), a leading provider of innovative technologies and solutions for mission-critical national security programs for the Intelligence Community and the Departments of Defense, State, Homeland Security, Justice, and other U.S. federal government customers, will announce first quarter 2005 financial results on Wednesday, May 4, 2005, after the market close. Following the release, ManTech will host a conference call to discuss the first quarter 2005 results, as well as comment on the outlook for 2005.

SPECIAL ManTech has moved the date of its first quarter earnings NOTE: out approximately one week, versus the traditional first quarter earnings announce date of late April - to accommodate a change in the company's schedule. The company's chairman and CEO, George J. Pedersen, will be receiving a very prestigious industry award on April 27, and ManTech's management team will be out of town attending the event.

WHO: On the call will be Mr. Pedersen; Robert A. Coleman, President and COO, ManTech International Corporation; and Ronald R. Spoehel, Executive Vice President and CFO, Mantech International Corporation.

WHEN: Wednesday, May 4, 2005

TIME: 5:00 p.m. Eastern Time

DIAL IN: (800) 819-9193 (Domestic); or (913) 981-4911 (International)

WEB Live Web cast of the conference call via ManTech's ACCESS: website: www.mantech.com. To access, click on the ManTech Investor Relations button.

REPLAY A replay of the call will be available beginning at INFORMATION: 9 p.m. on May 4, 2005, and will remain available through midnight on May 18, 2005. To access the replay dial (888) 203-1112 (Domestic); or (719) 457-0820 (International). Pass Code 9359641.

CONTACT Lisa Robinson - lisa.robinson@mantech.com or 703-218-6082 FOR CALL:

MEDIA/ Media Contact Investor Contact INVESTOR Mark Root Maureen Crystal CONTACTS: off: 703-218-8397; 703-218-8262 cell: 703-407-9393 maureen.crystal@mantech.com mark.root@mantech.com

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CONTACT: Mantech International Corporation Mark Root, 703-218-8397 (Media) cell: 703-407-9393 mark.root@mantech.com Maureen Crystal, 703-218-8262 (Investor) maureen.crystal@mantech.com

KEYWORD: VIRGINIA INDUSTRY KEYWORD: LEGAL/LAW AEROSPACE/DEFENSE GOVERNMENT SOFTWARE EARNINGS CONFERENCE CALLS SOURCE: Mantech International Corporation

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