This study designed to examine the smoking behaviour and attitude of children were carried out on 3447, 11 to 18 year old Sri Lankan School children. The prevalence of smoking in urban and rural children are 7.2% and 4.3% respectively. 0.5% of children chew tobacco or use tobacco snuff. Friends smoking behaviour and attitude are the best predictors of smoking in children. The knowledge of health hazards of smoking is poor and is related to smoking behaviour.