On 22 July 1950, shortly after the start of the Korean War, she was reactivated by the Navy for operation by the Military Sea Transportation Service.

She remained in the western Pacific, shuttling troops from Japan, as well as the Philippine Expeditionary Forces To Korea (PEFTOK), into June 1951; then returned to the United States to embark more soldiers for transportation to the Far East.

She continued to carry American troops on trans-Pacific voyages and shuttle runs between Japanese ports and between Japan and Korea until April 1952.

By the end of July, she had conducted a round-trip run to Bangkok out of Sasebo and was en route to the Aleutian Islands, whence she returned to the west coast for inactivation.

Sylvester Antolak arrived at Seattle on 10 August and was returned to the Maritime Administration on 17 September for berthing in the National Defense Reserve Fleet.