[1] Boston (along with Canberra and Chicago) was not recommissioned for service during the Korean War as were 10 others of her class, but was earmarked for conversion to carry guided missiles and reclassified CAG-1 on 4 January 1952.

In February 1952 she was towed from Bremerton, Washington, to Philadelphia for conversion to a guided missile heavy cruiser by New York Shipbuilding Corporation, Camden, New Jersey.

After making a Midshipmen's cruise to South America, taking part in NATO exercises in the North Atlantic, and receiving an overhaul, Boston made her second Sixth Fleet tour during June–September 1958.

During the next eight years, she frequently operated in the Mediterranean, often in the role of flagship, taking part in exercises off Northern Europe, the Caribbean and off the US East Coast.

[2] In April 1967, Boston returned to the Pacific for the first time in fifteen years, transiting the Panama Canal to begin a tour of combat service with the 7th Fleet.

Though she retained her Terrier missiles, the swift advance of technology had made these weapons obsolete after little more than a dozen years' service, and her main battery was once again her six, eight-inch guns, of her forward turrets.

On 16–17 June 1968, Boston was conducting naval gunfire support against North Vietnamese targets, in company with the destroyers USS Edson, USS Theodore E. Chandler and the Australian guided missile destroyer Hobart, when the group was attacked by USAF aircraft from the 366th Tactical Fighter Wing.

[4][5] Analysis determined that the missiles were AIM-7 Sparrow, designed to be used in an air-to-air role, and not in the inventory of Vietnamese People’s Air Force.

With the reduction in defense spending, funds were reallocated to more modern ships and Boston sailed for a last visit and family day at her namesake city in late 1969 before decommissioning.

Senator Edward Kennedy had expressed views that she should be retained as a museum ship on the city's waterfront but no plans materialised so she began the inactivation process at Boston Navy Yard's Naval Annex, on the 5 May 1970, was stricken from the Naval Vessel Register in January 1973 and sold for scrapping in March 1975.