Between commissioning and the end of January 1945, Aaron Ward completed fitting out and conducted her shakedown cruise off the California coast. On 9 February, she departed San Pedro, bound for Pearl Harbor where she arrived on 15 February. The warship conducted additional training in Hawaiian waters before loading supplies and ammunition and getting underway on 5 March to join the US 5th Fleet at Ulithi. She entered the lagoon of that atoll in the Western Carolines on 16 March but put to sea again on 19 March with Task Force 52 bound for the Ryukyu Islands.
The Mine Flotilla, of which Aaron Ward was a unit, arrived off Okinawa late on 22 March. The following day, the destroyer minelayer got her first glimpse of the enemy when some of his planes approached the sweep group but did not attack. More came in later, but the combined gunfire of the group dissuaded them from approaching close enough to harm the American ships. The first actual air raid occurred on the 26th, and USS Adams knocked the intruder out of the sky.
Aaron Ward supported minesweeping operations around Kerama Retto and Okinawa until the time of the first landings. During that period, she accounted for three enemy aircraft. On 1 April, the day of the initial assault on Okinawa, the destroyer minelayer began screening the heavy warships providing gunfire support for the troops ashore. T hat duty lasted until 4 April when she departed the Ryūkyūs and headed for the Marianas. She arrived at Saipan on the 10 April but shifted to Guam later that day. After several days of minor repairs, Aaron Ward headed back to Okinawa to patrol in the area around Kerama Retto. During that patrol period, she came under frequent air attack. On the 27 April, she shot down one enemy plane, and the next day, accounted for one more and claimed a probable kill in addition. Then she returned to Kerama Retto to replenish her provisions and fuel. While she was there, a kamikaze scored a hit on USS Pinkney. Aaron Ward moved alongside the stricken evacuation transport to help fight the inferno blazing amidships. While so engaged, she also rescued 12 survivors from Pinkney.
On 30 April, the destroyer minelayer returned to sea to take up position on radar picket station number 10. That night, she helped repulse several air attacks; but, for the most part, weather kept enemy airpower away until the afternoon of 3 May. When the weather began to clear, the probability of air attacks rose. At about dusk, Aaron Ward's radar picked up bogies at distance; and her crew went to general quarters. Two of the planes in the formation broke away and began runs on Aaron Ward. The warship opened fire on the first from about and began scoring hits when he had closed range to . At that point, he dipped over into his suicide dive but crashed about off the destroyer minelayer's starboard quarter. The second of the pair began his approach immediately thereafter. Aaron Ward opened fire on him at about and, once again, began scoring hits to good effect — so much so that her antiaircraft battery destroyed him while he was still away.
At that point, a third and more determined intruder appeared and dove in on Aaron Ward's stern. Though repeatedly struck by antiaircraft fire, the plane pressed home the attack with grim determination. Just before crashing into Aaron Ward's superstructure, he released a bomb which smashed through her hull below the waterline and exploded in the after engine room. The bomb explosion flooded the after engine and fire rooms, ruptured fuel tanks, set the leaking oil ablaze, and severed steering control connections to the bridge. The rudder jammed at hard left, and Aaron Ward turned in a tight circle while slowing to about . Topside, the plane itself spread fire and destruction through the area around the after deckhouse and deprived mount 53 of all power and communication. Worse yet, many sailors were killed or injured in the crash.
For about 20 minutes, no attacking plane succeeded in penetrating her air defenses. Damage control parties worked feverishly to put out fires, to repair what damage they could, to jettison ammunition in danger of exploding, and to attend to the wounded. Though steering control was moved aft to the rudder itself, the ship was unable to maneuver properly throughout the remainder of the engagement. Then, at about 1840hrs., the ships on her station came under a particularly ferocious air attack. While USS Little was hit by the five successive crashes that sank her, LSMR-195 took the crash that sent her to the bottom; and LCSL-25 lost her mast to a suicider. Aaron Ward also suffered her share of added woe. Just before 1900, one plane from the group of attackers selected her as a target and began his approach from about . Fortunately, the destroyer minelayer began scoring hits early and managed to shoot down the attacker when he was still away. Another enemy then attempted to crash into her, but he, too, succumbed to her antiaircraft fire.
Her troubles, however, were not over. Soon after the two successes just mentioned, two more Japanese planes came in on her port bow. T hough chased by American fighters, one of these succeeded in breaking away and starting a run on Aaron Ward. He came in at a steep dive apparently aiming at the bridge. Heavy fire from the destroyer minelayer, however, forced him to veer toward the after portion of the ship. Passing over the signal bridge, he carried away halyards and antennae assemblies, smashed into the stack, and then crashed close aboard to starboard.
Quickly on the heels of that attack, still another intruder swooped in toward Aaron Ward. Coming in just forward of her port beam, he met a hail of antiaircraft fire but pressed home his attack resolutely and released a bomb just before he crashed into her main deck. The bomb exploded a few feet close aboard her port side, and its fragments showered the ship and blew a large hole through the shell plating near her forward fireroom. As a result, the ship lost all power and gradually lost headway. At that point, a previously unobserved enemy crashed into the ship's deckhouse bulkhead causing numerous fires and injuring and killing many more crewmen.
As if that were not enough, Aaron Ward had to endure two more devastating crashes before the action ended. At about 1921, a plane glided in steeply on her port quarter. The loss of power prevented any of her 5 inch mounts from bearing on him, and he crashed into her port side superstructure. Burning gasoline engulfed the deck in flames, 40-millimeter ammunition began exploding, and still more heavy casualties resulted. The warship went dead in the water, her after superstructure deck demolished, and she was still on fire. While damage control crews fought the fires and flooding, Aaron Ward began to settle in the water and took on a decided list to port.
She still had one ordeal, however, to suffer. Just after 1920, a final bomb-laden tormentor made a high-speed, low-level approach and crashed into the base of her number 2 stack. The explosion blew the plane, the stack, searchlight, and two gun mounts into the air, and they all came to rest strewn across the deck aft of stack number 1. Through the night, her crew fought to save the ship. At 2106, USS Shannon arrived and took Aaron Ward in tow. Early on the morning of 4 May, she arrived at Kerama Retto where she began temporary repairs. She remained there until 11 June when she got underway for the United States. Steaming via Ulithi, Guam, Eniwetok, Pearl Harbor, and the Panama Canal, Aaron Ward arrived in New York in mid-August. On 28 September 1945, because her damage was so severe and the Navy had a surplus of destroyers at the time, she was decommissioned, and her name was struck from the Navy list. In July 1946, she was sold for scrapping. Her anchor is on display in Illinois.