"Alamo" returned to Subic Bay on the last day of July. On 5 August, she sailed with Marine Corps Battalion Landing Team 3/1 (BLT 3/1) embarked for patrol duties off the coast of South Vietnam and, through most of the autumn, alternated periods of leave and upkeep at Hong Kong and Subic Bay with Vietnamese patrol duty through 2 December. The ship arrived back in San Diego on 18 December 1964. Participation in Operation Silver Lance off the coast of southern California lasted from 23 February through 10 March 1965. On 11 March, "Alamo" was called upon to make an unscheduled run to Yokosuka carrying men and equipment for the American military buildup in the Far East as the United States was beginning direct participation in operations in Vietnam. She returned to San Diego on 12 April. The ship made a second unscheduled deployment to WestPac on 25 May. She sailed to Okinawa, onloaded Marines, then landed them at Qui Nhon and Danang, Vietnam. "Alamo" touched briefly at Yokosuka, then headed back to San Diego. She took part in Operations Cleansweep and Ragweed during September, devoted most of the autumn to training exercises, and ended the year in port at NS San Diego. In February 1966, the ship began her seventh major deployment to Westpac. "Alamo" spent six months operating as a part of an amphibious ready group (ARG) and shuttled troops and equipment from Subic Bay and Okinawa to various points in Vietnam. She returned to the United States in August. In September, her home port was switched to Naval Station Long Beach, California, and she was assigned to the newly formed Amphibious Squadron 7. In early 1967, she entered drydock at the Todd Shipyard in San Pedro, California, for her third major overhaul which, with the ensuing series of refresher training exercises, accounted for most of the year. In November, the ship sailed for the Far East. There, "Alamo" was engaged in a series of lifts from Guam and the Philippines to Da Nang. She also again became a member of an ARG and operated along the Vietnamese coast for much of her tour. The ship also participated in four amphibious operations before returning to Long Beach in June 1968. The ship engaged in local operations along the West Coast for the rest of 1968. On 30 January 1969, she began another WestPac deployment in which she lifted troops and equipment to Da Nang and then proceeded to Subic Bay where she joined ARG "Bravo."