World War II
From 20 September to 19 October 1944 Douglas A. Munro served as escort for Vixen carrying Admiral R. E. Ingersoll, Commander-in-Chief, Atlantic Fleet on a tour of Caribbean defenses. She voyaged to Casablanca as escort for Kasaan Bay between 24 October and 14 November.
She then left Norfolk, Virginia, 7 December, for the Pacific Ocean. After exercising at Manus, she sailed to Biak, Schouten Islands, to pick up a convoy of LSTs and merchant ships bound for Lingayen Gulf, arriving there 9 February.
Douglas A. Munro returned to San Pedro Bay, Leyte, and on the 20th sailed to escort a convoy of U.S. Army tugs to Subic Bay. Upon her arrival a week later she was assigned to screen a minesweeping unit clearing the San Bernardino Strait and the approaches to Manila Bay, and also supported naval and amphibious operations on nearby shores. She operated at Subic Bay until 6 May.
Douglas A. Munro served in the assault and occupation of Borneo from 19 May to 5 July 1945. She escorted supply convoys from Leyte, bombarded enemy positions, and served as antisubmarine patrol vessel. She escorted transports from Ulithi to the Philippines from 19 to 26 July, then patrolled against submarines between Leyte and Okinawa until the end of the war.
Douglas A. Munro cleared Leyte 6 September to join the South China Force, arriving in the approaches to the Yangtze River on the 19th. She served with this force until 5 January 1946 when she got underway from Hong Kong for the U.S. West Coast, arriving at San Francisco, California, 1 February. Moving to San Diego, California, 30 March, she was placed out of commission in reserve there 15 January 1947.
Korean War
USS Douglas A. Munro was recommissioned on 28 February 1951. On 8 July of the same year, the Douglas A. Munro sailed from San Diego to Pearl Harbor. During their passage, the boat and crew rescued a civilian who had been washed overboard during the Transpacific Yacht Race. After training until 29 October, the DE-422 was on her way to Korean waters to serve with the United Nations Blockading and Escort Force; participating in the siege and bombardment of Wonsan Harbor. The boat was also active in rescue work. While on patrol in the Formosa Straits on 25 January 1952 the Douglas A. Munro aided the Chinese Nationalist dredger Chien Wong. Later, on 12 February, DE-422 assisted the British merchant vessel SS Wing Sang who had been attacked by Communist pirates. Douglas A. Munro, under the command of Struyk, also rescued two crew members of a crashed torpedo bomber and picked up two U.S. Marine colonels whose helicopter had crashed on an island in the Han River estuary. The USS Douglas A. Munro returned to Pearl Harbor on 24 May 1952 for overhaul and training.