The ship was laid down as LST-329 on 12 November 1942, at the Philadelphia Navy Yard; reclassified ARB-1 on 25 January 1943; launched on 1 February 1943; sponsored by Mrs. Arthur Taylor; converted at Fairfield, Maryland, by the Maryland Drydock Company for service as a battle damage repair ship; and commissioned on 18 May 1943.

As a member of Service Squadron (ServRon) 10, she performed battle damage and voyage repairs to various ships of the fleet.

On 2 July, the ship moved her base of operations to Buckner Bay, Okinawa, where she provided routine repair services.

Aristaeus' repair efforts, however, enabled the battleship to get underway for Pearl Harbor on 24 August, nine days after the Japanese capitulation ended hostilities.

The ship reached San Francisco, California, on 27 December, and entered a period of upkeep and repairs.