This study estimates the individual and joint prevalence of cigarette smoking and alcohol misuse, and examines the association between these risks and socioeconomic factors in Thailand. The self-reported data on cigarette and alcohol use are from a 2004 nationally representative cross-sectional survey of 39290 individuals aged 15 and over. Substantially more men than women were current smokers (45.8% vs. 2.3%; p<0.001) as well as harmful (5.4% vs. 0.9%, p<0.0001) and hazardous alcohol users (11.2% vs. 1.2%, p<0.001). The strongest predictor of alcohol misuse was smoking, and the strongest predictor of smoking was alcohol misuse in both sexes. There was an inverse relationship between education and family income with the odds of current smoking, whereas average levels of family income (not low or high) were associated with higher odds of harmful or hazardous alcohol use. Tobacco and alcohol misuse could be more effectively addressed by targeting and tailoring programs towards those who are most at risk - joint tobacco and harmful or hazardous alcohol users, and those of lower socioeconomic status.