Later, it was re-formed in July 1940 for service during the Second World War, the brigade was initially a formation of the Second Australian Imperial Force assigned to the 8th Division; however, after its sub units were captured by the Japanese in 1942 it was reformed with Militia battalions and was mainly used in a garrison role around Darwin, in the Northern Territory, until late in the war when it was committed to the fighting against the Japanese on Bougainville.

The brigade's constituent units were spread across various locations in Tasmania including Lyell, Zeehan, Burnie, Devonport, Deloraine, Beaconsfield, Launceston, Scottsdale, Hobart and Huon.

[1] The formation was short lived, and was not raised as part of the First Australian Imperial Force (AIF) during the First World War.

Broken up and sent piecemeal to reinforce the garrisons at Rabaul, Ambon and on Timor, the 2/21st, 2/22nd and 2/40th Battalions were all eventually destroyed or captured by the Japanese in early 1942.

[12] While its constituent battalions were deployed, the brigade's headquarters remained intact in Darwin, and consequently it was reinforced with replacement units from the Militia, beginning in December 1941.

[5] In March 1942, Brigadier Ivan Dougherty assumed command of the brigade[8] which was assigned to the 12th Division (Northern Territory Force).

[18] However, in April 1945 the brigade was committed to the fighting on Bougainville Island, where they took over responsibility for the central and northern sectors, engaging the Japanese in direct combat for the first time, carrying out patrolling operations and launching a number of small attacks.

[15][19][20] During one of these attacks, north of Ratsua, one of the 8th Battalion's members, Private Frank Partridge, performed the deeds that led to him being awarded the Victoria Cross.

[20] Following the end of hostilities, the brigade remained on Bougainville guarding Japanese prisoners as the demobilisation process began.