In August 1942, the regiment's first battery, the 9th, deployed to Milne Bay in support of the 18th Brigade, as Japanese forces advanced along the Kokoda Track towards Port Moresby. They subsequently took part in the Battle of Milne Bay, while the rest of the regiment was preparing for deployment around Woodford, arriving in October. The 55th Battery subsequently took part in the capture of Buna, being moved by sea from Oro Bay aboard several luggers. During the move, the vessels were attacked and two guns were lost, as well as several personnel killed. They subsequently supported the 18th Brigade and US 32nd Infantry Division. Meanwhile, the 10th Battery undertook defensive duties around Porlock Harbour and on Goodenough Island. The regiment's batteries were progressively relieved between February and April 1943, after which it concentrated around Port Moresby, remaining there until January 1944, when they returned to Brisbane having spent the remainder of its time in New Guinea carrying out garrison duties.