The association of sociodemographic and selected behavioral and social environmental factors with successful smoking cessation was examined using cross-sectional data from the 1998 Australian National Drug Strategy Household Survey, which used an area multistage stratified design. Data collection involved a mixture of interviews and self-administered questionnaires. We used a subsample of 2,526 Australians aged 14 years and older. The outcome measure distinguished between current smokers and those who had stopped smoking in the past 2 years and had not smoked for at least 1 month prior to the survey. Knowing that environmental tobacco smoke is harmful and having first smoked at age 14 or younger were associated with a higher likelihood of cessation. The odds of having quit smoking were 4.5 times greater for respondents who lived in households where smoking was not permitted than for those in households with no smoking restrictions. The odds of having quit were 3.2 times greater for respondents who reported that few or none of their friends smoked than for those who said most or all of their friends smoked. After including social environmental variables, associations of education and cessation disappeared. The study confirmed the difficulty of quitting if the proximal social environment is filled with smokers. Results call for an integrated approach in which smoking cessation interventions target the social environment as well as the individual. Efforts to intervene in smoking behavior will have limited effectiveness unless they take into account the social contexts in which smoking behavior takes place.