Fechteler operated with the Seventh Fleet in support of United Nations Forces during the Korean War, underwent conversion to a radar picket destroyer from 1 April to 1 December 1953, alternated operations along the west coast and in Hawaiian waters with deployments to the western Pacific with the Seventh Fleet, and participated in Sea Dragon and Market Time operations, patrolled on search and rescue duties and carried out naval gunfire support missions during the Vietnam War.

Fechteler completed a second tour of duty in the Far East in 1949, and in June 1950, when the Korean War broke out, was at sea off San Francisco on exercises.

During both of these, she screened TF 77 in its air operations, sailed with the escort and patrol force, and gave bombardment and close gunfire support to the troops ashore.

In addition to participating in the Atlantic schedule of east coast and Caribbean exercises, she also joined in a midshipman cruise in the summer of 1955, voyaging to Málaga, Spain; Plymouth, England; and Guantánamo Bay, Cuba.

In 1956, 1957–58, 1958–59, and 1960, she cruised in the Far East on duty with the 7th Fleet, serving both on the Taiwan Patrol, and with carrier task forces as a radar warning ship.