Objectives-To study the prevalence and determinants of cigarette smoking among Saudi nationals in three regions of Saudi Arabia. Participants-A sample of 8310 individuals aged 15 years and above from both sexes, randomly selected from the three regions, using a stratified cluster sampling technique. Design-A cross-sectional, household, community-based survey. Using a predesigned and tested questionnaire, the participants were interviewed by primary care physicians. The interview covered personal, social, and educational characteristics of the respondents, and also included questions about their smoking status, duration of smoking, and daily cigarette consumption. Main outcome measures-Association between current smoking and sociodemographic variables, in univariate and multivariate analysis. Degree of interaction between the diVerent determinants of cigarette smoking. Results-The overall prevalence of current smoking was 21.1% for males and 0.9% for females. Most smokers (78%) were young to middle-aged (21-50 years old). Smoking prevalence was higher among married people, among uneducated people, and among those in certain occupations: manual workers, businessmen, army oYcers, and oYce workers. Conclusions-Cigarette smoking is an important public health problem in Saudi Arabia. A more intense and comprehensive tobacco control eVort is needed. (Tobacco Control 1999;8:53-56)