This bulletin presents results from the 2012 National Prisoner Health Data Collection, focusing on smoking and smoking cessation behaviours of prisoners in Australia. In 2012, 84% of prison entrants were current smokers, which is around 5 times the proportion of the general community. Quitting smoking in prison is difficult: 35% of prisoners who were about to be released tried to quit during their time in prison, but only 8% were successful.