This study analyzes how the United States Army component of the Military Assistance Command-Vietnam (MACV) attempted to measure its progress and effectiveness while conducting counterinsurgency operations during the Vietnam War. It illustrates the difficulties staff officers and commanders confronted in identifying useful metrics for gauging success in an unconventional environment. Political, economic, and cultural factors all impinged on the course and conduct of the army's counterinsurgency operations. These factors also influenced how commanders attempted to assess their effectiveness and progress. From a historiographical standpoint, most secondary literature on the Vietnam War maintains that the U.S. Army simply used body counts to measure its military effectiveness in a counterinsurgency environment. These sources contend that since army officers could not depend on traditional measures such as geography to determine if they were winning or losing, they reverted to the organizationally comfortable procedure of counting enemy dead. The purpose of this study is to correct this inaccurate simplification and, more importantly, to discover how the U.S. Army, confronted by an unfamiliar enemy and form of warfare, attempted to measure its successes and failures. It will do so by examining the army's doctrine for counterinsurgency, its formulation of measurements to assess progress in the Vietnam War, and the army's use and modification of these measurements during a long and complex war. In the process, this study investigates the army's efforts to measure its progress and effectiveness in a number of key areas throughout the conflict: counterinsurgency operations, search and destroy missions, pacification efforts, and the training of South Vietnamese forces.