From December 1967 to December 1968, Palm served in Vietnam as a Forward Observer and Fire Direction Officer in the 1st Battalion, 13th Marines at Khe Sanh. He also commanded a 155 mm gun platoon and 8" platoon of the 5th 155 mm Gun Battery. Upon returning to the United States he was assigned to Fort Sill as a gunnery instructor in both the basic and career branches. While in this assignment, he was promoted to captain on December 1, 1970.