Video shot by a passenger showed smoke in the cabinet as staff prepared to get passengers off the aircraft on landing.
Jetstar said there had been a technical fault with an engine.
The budget airline denied it was an emergency landing and said smoke entered the cabin only after the plane landed.
But some passengers reported hearing a noise and smoke filling the cabin while the plane was still in the air.
Passenger Nick Trompf told the Courier Mail it had been "pretty scary",