This article examines the preparation and contents of the ROKFV’s (Republic of Korea Forces in Vietnam) civil affairs operations and civil-military relations, as well as the conflict between the Korean military and the Vietnamese community, based on oral statements of veterans. Since most battles in Vietnam were conducted as counter-guerilla warfare, the distinctions between the front and the rear were unclear. Therefore, the Korean military should have established friendly relationships with the Vietnamese community for successful operations. However, according to the veterans, ROKFV’s preparations for civil-military relations were generally poor. Special training conducted just before the dispatch to Vietnam only focused on combat skills such as guerrilla training, ignoring education on Vietnamese culture and custom that are essential for successful civil relations. It was inevitable that special training concentrated on improving combat skills because the basic mission of soldiers was a battle, but the actual preparations for civil-military relations were relatively insufficient, compared to the Korean military’s externally avowed commitment to the importance of civil relations in Vietnam. ROKFV’s civil affairs operations consisted of relief works, medical treatment, construction, and self-help projects. The operations were influenced by the United States’ counterinsurgency doctrines and modernization theory. In other words, the large-scale civil affairs operations conducted by ROKFV were carried out under the material and theoretical background provided by the U.S. Many veterans gave a negative assessment of the effects or results of the civil affairs operations. This raises question of whether the historical image of the Korean military’s ‘successful civil-military relations’ in Vietnam War has been largely mythical.