As a unit of task force TF 90, she conducted a check sweep of Inchon harbor, and then took station in the outer screen of the antisubmarine patrol.

At the end of the month, having been transferred to task force TF 95, she proceeded to Kunsan, where she swept her first mine of the Korean War, and then returned to Sasebo.

Her availability period cut short by the Hungnam evacuation, Mockingbird returned to Pusan in late December and the following month conducted a "cleanup" sweep of the Korean east coast from the 39th parallel to Pohang to provide easy access to the beaches for the fire support ships of TF 95.

For the remainder of the war, Mockingbird alternated between the east and west coasts of Korea, sweeping chant nets and conducting anti-junk patrols from Chinnampo and Haeju, south to Mokpo and around the peninsula to Wonsan, Hungnam, and Songjin.

Following the signing of the Truce Agreement, 27 July 1953, Mockingbird became a unit of the escort and blockading forces which remained on patrol off Korea.