 In May 1966, he joined Company D, 1st Battalion, 3rd Marines, 3rd Marine Division in the Republic of Vietnam, and served consecutively as fire team leader, squad leader, and non-commissioned officer in charge of the Combined Action Company.He was promoted to Sergeant on September 1, 1966.In November 1966, he served on temporary additional duty as company gunnery sergeant with Headquarters Company, 7th Engineer Battalion (Combined Action Company).