Unlike many of her sister-ships, she was never decommissioned during the wars, serving in her entire life in the Pacific.

In the early months of the war she served as an escort, and then was assigned to fleet activities, and in this role she participated in the Battle of Java Sea, in the force ABDA. On 19 February, 1942 this fleet was attacking landing forces at Bali. In this engagement she came under very accurate fire from Japanese destroyers, and suffered extensive damages to her hull, engine rooms, as well as to her armament. She kept on fighting, and escaped, reaching Surabaya on her own power.

In the dry dock, while being lifted, the shore collapsed, and Stewart (Lt. Cdr. Harold Page Smith) rolled to a 37 degree angle. Amazingly no one was hurt or killed, but more damage was done to her hull, and because of the rapidly advancing Japanese forces, she was left behind and blown up. At least so the American Navy thought.

In reality she was recovered by the IJN, and after certain changes to her stacks and her armament (the IJN wanted to make sure she wouldn't be misidentified and attacked by their own forces) they commissioned her as Patrol Boat No.102 She was never really patched up, only 2 of her four boilers were operational, but nevertheless she was seaworthy, and soon started ASW patrols around the Japanese-held islands in the Pacific. And soon American pilots started to file in reports about a strange, unrecognizable IJN destroyer, which strongly resembled to the old four-stack destroyers. These reports were dismissed.

However, the story of the "Phantom Destroyer" was soon born. USS Stewart may have served well the United States of America - so did she serve the Japanese Empire.

Although both cases are very far away from verified, she might have been involved in the sinking of at least two American submarines. One could be USS Harder (SS-257) on 24 August, 1944. Along with USS Haddo, she was operating in the vicinity of Dasol Bay. So did Patrol Boat No. 102, and the two US subs became under heavy depth charge attacks. USS Harder was never heard from again, and USS Haddo reported that a massive amount of around 400 depth charges were used in the attack. Although nothing confirms that some of it was dropped by Patrol Boat No.102, much less proof for delivering the fatal blow, it is very likely the the former US destroyer was involved in this engagement.

In the other case she is strongly suspected to sink the famous USS Growler (SS-215) on 8 November, 1944, in the South China Sea. Although there is no confirmation, on this occasion there wasn't as many other IJN ships in the vicinity, making her a perfect candidate.

On 28 April, 1945 she was at Mopko, Korea, when she was damaged by US aircraft. She limped back to Kure/Hiroshima for repairs, but never set sail again. She was there when the atomic bomb was dropped on Hiroshima.

After reclaimed by the US Navy, there was a bit of confusion, nobody knew what to do with her. Some thought she should be preserved as a memorial, but finally she was used and sunk as a target ship off San Francisco on 24 May, 1946.