In January 1943, the regiment returned to Australia aboard the transport "Ile de France" as part of the final of the transference of Australian ground troops from the Middle East to the Pacific. After leave, the 2/12th re-formed at Kairi, on the Atherton Tablelands in Queensland in April 1943. A period of reorganisation and training followed as the 2/12th was prepared for the rigours of jungle warfare. In late July, they embarked by detachments at Cairns upon several transports including , "Van Heutz", "W Ellery Channing", and the "Van Der Lijn", bound for New Guinea where they were to join the fighting against the Japanese. After arriving at Milne Bay in August, they subsequently took part in landings around Lae and then Finschhafen in September, and saw action during the Huon Peninsula campaign. Supporting the 20th Infantry Brigade during the initial landing around Scarlet Beach, once Finschhafen was secured, the regiment's guns support the attack on Sattelberg from the coastal plain, before supporting further advances north as part of the drive towards Sio before returning to Australia in early 1944. After a year-long interlude training around Ravenshoe, Queensland, the regiment undertook its final campaign of the war in 1945, providing fire support during the Battle of North Borneo. Assigned to support the 24th Infantry Brigade, during the landing on Labuan two troops of the 2/12th came ashore alongside the assaulting infantry in LVTs, something the Australian Army had not done before. Later, during June, 14 guns from the regiment were moved by barge to support operations around Weston and Beaufort. The swampy ground in the area posed problems for the gunners, who had to shore up the ground with coconut palms. At the end of the war, the regiment was disbanded with its last war diary entry being made on 1 March 1946.