Brunswick departed Galveston on 15 October 1944 on her way to shakedown training in the West Indies. She arrived in the vicinity of Bermuda and underwent her shakedown evolutions between 24 October 1944 and 22 November 1944.
Brunswick embarked upon the first of her three round-trip convoy escort missions to North Africa on 11 December 1944. Steaming from Hampton Roads, Virginia, she arrived in Oran, Algeria, with Convoy UGS-63 on 28 December 1944. On 2 January 1945, she stood out of Oran in the screen of Convoy GUS-63. Soon after the convoy passed through the Strait of Gibraltar, one of its ships, the merchant ship SS Henry Miller, suffered a torpedo hit from the GermansubmarineU-870. Brunswick conducted a depth-charge attack, but U-870 escaped. Brunswick escorted the damaged Henry Miller into Gibraltar and then rejoined the convoy screen. She and the rest of the convoy arrived safely in Hampton Roads on 20 January 1945.
Between early February and early June 1945, Brunswick escorted merchant ships on two more round-trip voyages from Hampton Roads to Oran and back. She returned to the Norfolk, Virginia, area from the last of those voyages on 6 June 1945.
Postwar
From Norfolk, Brunswick moved north to Philadelphia, Pennsylvania, where the Philadelphia Navy Yard converted her for duty as a weather ship. She embarked upon her first weather patrol early in July 1945 and concluded her final one on 12 November 1945. Thereafter, Brunswick served in the U.S. Coast Guard temporarily.
Returned to the Navy at Norfolk early in April 1946, Brunswick was decommissioned there on 3 May 1946. Her name was struck from the Navy List on 19 June 1946, and she was sold on 9 April 1947 to the Sun Shipbuilding and Drydock Company of Chester, Pennsylvania, for scrapping.