With the outbreak of hostilities in Korea, "Diphda" was assigned to Service Force, Pacific (ServPac), for duty as an ammunition ship. She made an emergency delivery of ammunition at Pusan, Korea, and offloaded the remainder of her cargo at Yokosuka before returning to San Francisco on 12 September 1950. Six days later, she got underway for an extended tour in Korean waters during which she carried ammunition between depots in Japan and Korea and to combat units and ships. On 26 December, she replenished heavy cruiser at sea. "Diphda" returned to San Francisco on 29 October 1951 for overhaul.