Following her completion on 26 December 1944, Toro participated in training exercises out of Portsmouth, New Hampshire, Newport, Rhode Island, and New London, Connecticut, before arriving at Key West, Florida, on 11 February 1945.

She provided services to the Fleet Sonar School, then, on 28 February, departed Key West in company with submarine Bumper (SS-333), bound for the Panama Canal Zone where she underwent a week of intensive training.

After arriving in her patrol and lifeguard area south of Shikoku and east of Kyūshū on 16 May, she occasionally encountered Japanese planes as she pursued her duties.

On 18 May, following a probable periscope sighting, Toro detected a transmission on Japanese submarine radar frequency and attempted to close the contact but was unsuccessful.

The departure of Toro’s air cover at 18:00 left her in a most dangerous situation due to the expected passage of an American task force on an antishipping sweep.

[7] Toro crash-dived and attempted to establish her identity using a flare, smoke bombs, and sonar, but the ships were still firing when she passed 150 feet (46 m).

[7] The surface vessels, thinking that Colahan had sunk a Japanese picket boat, remained in the area for half an hour searching for survivors without discovering that their target had been a friendly submarine.

During the next ten years, she combined these activities with type training and services to ships and aircraft engaged in antisubmarine warfare exercises.

She was redesignated an auxiliary submarine with hull classification symbol AGSS in July 1962 and, on 22 November 1962, as her Navy career drew to its close, she made her 11,000th dive while operating in Long Island Sound.

In February 1963, she was ordered to berth with the Philadelphia Group, Atlantic Reserve Fleet, for demilitarization and non-industrial stripping; on 11 March 1963 she was decommissioned, and on 1 April 1963 her name was struck from the Naval Vessel Register.

She was slated to be sunk near the lost submarine Thresher (SSN-593) in an attempt to understand the currents near the wreck location but the plan was abandoned, and Toro was later sold and scrapped.