Tobacco If you are aged 18 years or over, you can bring 250 cigarettes, or 250 grams of cigars or tobacco products duty-free into Australia with you. All tobacco products in accompanied baggage are included in this category, regardless of where or how they were purchased.

250 cigarettes, or 250 grams of cigars or tobacco products for each passenger aged 18 years or over. One opened packet containing 25 cigarettes or less is also allowed. You can pool your duty free concessions if you are a family traveling together.

http://australia.visahq.com/customs/