Operation Iraqi Freedom was perhaps the last military campaign that will ever utilize the services of a mobile Army surgical hospital (MASH). The Army has now essentially replaced the MASH with combat surgical hospitals (CSH) and forward surgical teams (FST). MASH units were designed as mobile, flexible, forward-deployed military hospitals, providing care for the wounded near the frontlines of the battlefield. These hospitals not only saved thousands of lives during war but also greatly influenced the delivery of trauma and critical care in civilian hospitals. The MASH was made popular by the television series of the 1970s, depicting the 4077th during the Korean War. Although a comical series, these television episodes provided viewers with a glimpse of life in a MASH during time of war. This article chronicles the history of the MASH from its inception during World War II to recent experiences in Operation Iraqi Freedom.