The Regiment came into existence on 18 July 1940 with the appointment of Major J W Rhoden 2/IC 2/2nd Medium Regiment as Commanding Officer 2/3rd Lt A.A.Regt. The appointment of other Senior Officers followed. At the end of July 1940, Major Rhoden was promoted to Lieutenant-Colonel. The men were recruited from reception Depots at Geelong, Caulfield and Royal Park, Victoria. These drafts moved to Werribee Racecourse on 27 August 1940. Training as a Regiment began at once.
The 2nd / 3rd Regiment consisted of three Batteries, the 7th, 8th and 9th plus RHQ, Workshops and Signals Section. The Regiment was to be equipped with Bofors Guns on arrival in the Middle East. These Guns fired a 2lb shell at the rate of 120 rounds per minute.
The Regiment embarked on HMT Mauretania at Port Melbourne on 29 December 1940. The convoy arrived at Fremantle on 3 January 1941, where leave was granted from 0900 hrs to 2359 hrs. The Convoy sailed the following morning, Colombo was reached on the 14th January and following shore leave the Regiment transferred to HMT Devonshire. On 30 January the Regiment arrived at Haifa, and on the following day disembarked and moved by train and bus to Kassa Camp, where the 2nd/16th Infantry Battalion had erected tents and had an evening meal waiting for the Regiment. On 6 February 1941, 8th Battery moved out for Libya; this Battery had not been issued with any guns and on arrival at Tobruk had to make do with captured Italian 20mm Breda Lt A.A. Guns. Useful Guns, but much inferior to the Bofors Gun.
On 11 April 1941, 7th and 9th Batteries moved out of Kassa to join Lustre Force to defend Greece. Due to the rapid change in events in Greece, 7th Battery was ordered to Crete to take-over defence of British Air Bases on the island, and 9th Battery was ordered to the Western Desert to defend Air Bases in that area.
At a later date 9 Battery plus one Troop of 7 Battery took part in the Syrian Campaign.
Early in January 1942 the scattered elements of the 2nd / 3rd Regiment were brought together at Suez Transit Camp, prior to embarking on various ships for return to Australia. Embarking began on 4 February and continued through to March.
The main body of the Regiment embarked on the HMT Andes on 18 February; the Andes was a British passenger ship built just prior to the outbreak of war, and was still on her maiden voyage. The Andes reached Fremantle on 10 March 1942. WX numbers were allowed overnight leave. On 15 March the Andes berthed at Adelaide.
At the end of its service in the Middle East the Regiment had accounted for 101 Enemy Planes, but the loss in Officers and Men was very high; 162 Killed in Action or Prisoner of War.
On 12 April 1942, 9th Battery moved out from their billets in the Adelaide suburb of Paradise, en route to Queensland for Jungle Training, thence via Port Moresby to Milne Bay. On 14 April 1942 RHQ 7 and 8 Batteries moved out bound for Western Australia.
On arrival in Perth, 7th Battery was deployed with two troops to cover RAAF Base at Pearce and one troop at Leighton, 8th Battery had two troops at the Fremantle Harbour area, and one troop at the Catalina Flying Boat Base at Crawley Bay. RHQ was situated at Guildford.
By mid 1943, 7th and 8th Batteries were providing AA Defence in the Northern area of WA, at Geraldton Air Drome, Onslow and Exmouth Gulf; at this time the decision was made to disband 2nd/3rd Lt. A-A Regiment
As from 24 August 1943, 7th Battery became part of 2/2nd Composite A.A.Regiment (LE). As a result of a reorganisation of antiaircraft units, 8th Battery became an independent Airborne Battery, with the novel idea of transporting dismantled Bofors Guns with their crews in DC3 aircraft to newly captured airstrips. 9th Battery at Milne Bay was joined with 2nd/6th Heavy A-A Battery to form the 2nd/3rd Composite A-A Regiment. This Regiment also had a Searchlight Battery attached. Many of the members of the Searchlight Battery were West Australians from the 55th A-A Company.
Elements of the 2nd/3rd Lt AA Regiment took part in one form or another in various actions in New Guinea, the last one being Labuan In Borneo in June-July 1945.
No records are available in regards to Japanese Planes shot down during operations in New Guinea and Borneo.
Total Casualties:- K.I.A.: 66, POW: 135 Honours and Awards:- 2 Military Medals. 8 Mention in Despatches. Battle Honours:- Tobruk, Crete, Western Desert, Syria, Port Moresby, Milne Bay, Lae, Buna, Borneo.