This study examined smoking behavior among adolescents in Thailand and Malaysia. Population surveys of over 1,700 adolescents aged 13-18 found that approximately 5% of Thai and Malaysian adolescents were current smokers, while an additional 8-9% reported starting to smoke. Thai smokers reported first smoking a whole cigarette at age 14.6 on average, compared to 13.9 for Malaysian smokers. The majority of smokers in both countries bought cigarettes themselves, though Thai smokers were more likely to get cigarettes from friends. Thai adolescent smokers predominantly smoked factory-made cigarettes, while Malaysian smokers more often smoked hand-rolled cigarettes. Around half of smokers in both countries reported trying to quit smoking in the past month.