We specify causal models of the learning process implied in Akers’ (1977) social learning theory for the initiation and maintenance of adolescent cigarette smoking. Path analyses of data from a three-year panel study of junior and senior high school students indicate that the theory is more effective in accounting for maintenance (or cessation) of cigarette smoking than in explaining initiation to cigarette smoking. Most important, our measures of social and nonsocial reinforcement mediate the effect of differential association on smoking as social learning theory predicts.