ABSTRACT The Department of Defense (DOD), operating through the Directorate of Military Support in the Department of the Army, supports state, local and other federal agency response operations in a wide range of natural and man-caused emergencies. Examples within the past six years include the Ashland Oil tank collapse in Floreffe, Pennsylvania, Exxon Valdez cleanup, Loma Prieta earthquake, hurricanes Hugo and Andrew, Mexico City earthquake, Armero (Columbia) volcanic eruption, and Puerto Rico floods and mudslides. From March 24 to September 27, 1989, the period of the Exxon Valdez initial cleanup operations, DOD provided military and civilian personnel, U. S. Navy ships for housing response workers, cargo and medical evacuation aircraft (fixed wing and helicopters), skimmers, modified dredges, landing craft, Dracones, Zodiak boats, radios, computers, and other miscellaneous equipment. This was in addition to assets of the Alaska Army and Air National Guard, which were committed by the governor. Support was provided to the U. S. Coast Guard on-scene coordinator and supervised by the Alaska Oil Spill Joint Task Force. The General Accounting Office, in its January 1990 report, Federal Costs Resulting from the Exxon Valdez Oil Spill, estimated that DOD spent $62.8 million through September 30, 1989, the largest expenditure by any federal agency. Use of military resources is a realistic scenario in certain situations. Primary responders at the federal and state level should understand how to request and employ these assets. This paper provides a background on DOD support to disaster relief operations, and discusses the types of support available to agencies responding to natural or man-caused emergencies, request and approval mechanisms, the Department of Defense organization to provide support, and reimbursement of the department.