[2][1] Sphinx completed fitting out and proceeded to Norfolk, Virginia for sea trials and shakedown in Chesapeake Bay.

She operated in the central Pacific islands until entering Pearl Harbor, on 9 January 1947, en route to the west coast for decontamination.

The ship had participated in "Operation Crossroads," the atomic bomb tests at Bikini Atoll, in the Marshall Islands, from early April to 29 August 1946.

After outfitting and holding shakedown training, she stood out of San Diego, on 17 August 1951, and proceeded via Pearl Harbor to Japan.

The ship returned to San Diego, on 4 June 1952, and operated along the California coast until redeployed to the Far East from 3 March to 9 December 1954.

Sphinx moved to Dong Tam Base Camp, on 11 June, and was assigned to the Mobile Riverine Force in the Mekong Delta.

In addition to her regular duties, the ship served as the tactical operations center of the Can Giuoc Interdiction Unit and also developed helicopter capabilities, handling 50 landings before 31 December 1969.

On the last day of the year, the ship lost power in both main engines and was adrift 340 mi (550 km) from Sasebo.

[1] From September 1984 to July 1985, the ship went through a $25 million overhaul at the Puget Sound Naval Shipyard to become an intelligence-collection platform.

It conducted patrols off the Pacific coast of El Salvador, monitoring the actions of the communist guerrilla forces.

On 24 August, Sphinx was sold for scrapping to North American Recycling, Inc., Sparrows Points, Maryland, as part of a five ship contract worth $2,161,610.