In June 1943 the 25th was ordered into active military duty and transferred to Nichols General Hospital in Louisville, Kentucky. In July the unit’s officers and enlisted personnel received training at Fort Knox, Kentucky, learning to set up and operate a general hospital under field conditions. On December 19, 1943, the unit transferred to Camp Kilmer, New Jersey, and on December 23, embarked for the European Theater of Operations.
Arriving in Scotland on December 29, the unit moved by rail to Stockbridge, England, its inital site of operations, and then to Cirencester. In July 1944, the 25th departed for the continent, arriving
at Utah Beach and establishing the unit nearby at Lison. Subsequently, the 25th completed moves to Belgium (Liege, Morlanwelz, and Tongres). The final transfer before deactivation brought
the unit to Rouen, France.