Australian Minister for Defense Materiel Jason Clare said the weapons are the improved M3 model and were delivered over the past year. The final delivery installment was received last month.
The weapon is a recoilless rifle that can fire a variety of ammunition -- from anti-personnel projectiles to illumination rounds.
The weapon is normally operated by a two-man crew.
The Australian Defense Department says its Special Forces and Mentoring Taskforce 3 troops are using Carl Gustav guns in Afghanistan.
"The feedback from soldiers is that it is very effective," Clare said.
"It is used to knock down walls and blow up bunkers. It can also fire smoke-filled ammunition and lights to improve soldiers' visibility at night."
Clare said Saab would provide ammunition for the weapons for the next five years under a contract with a potential value of more than $100 million.