In order to identify predictors of long-term post-treatment smoking abstinence, 333 adult smokers who volunteered to participate in a smoking cessation program were asked to complete a set of questionnaires which measured self-efficacy, motivation, reasons for smoking, and smoking history variables. Subjects were then randomly assigned to one of four smoking cessation interventions. Nine variables predicted abstinance up to and including one year following treatment. The importance of self-efficacy beliefs in quitting smoking was underscored.