She returned to resume West Coast operations in July 1961 and entered the Long Beach Naval Shipyard on 6 October for major improvements in her communications and antisubmarine warfare (ASW) equipment.

During the summer of 1965, Parsons visited San Francisco, Puget Sound, and Hawaii as part of the Pacific Midshipman Training Squadron.

Following shakedown she carried out a rigorous testing program for her missile systems, and in September 1968 she assumed duties as flagship for Destroyer Squadron 31 (DesRon 31) and immediately deployed to the Western Pacific for operations with the Seventh Fleet off Vietnam.

The 5 in (127 mm) 54-caliber gun was, nominally, a rapid-fire mount capable of firing over 30 rounds per minute at targets up to ranges of 12 nautical miles (22 km).

After conversion, Parsons was homeported in San Diego, California, from re-activation until late 1971, when the ship, as part of Destroyer Squadron 15 (DesRon 15), was forward deployed to Yokosuka, Japan.

As part of this movement, the families of all eligible crewmen were transported to Japan, where they lived in U.S. Navy Housing, located in both the Yokosuka and Yokohama areas.