Smoking among adolescents is a developmental phenomenon with several factors exerting an influence on cigarette use at different times. We examined the longitudinal influences of several behavioral and social variables on the smoking status of 443 students followed from early to late adolescence. Of the factors examined, association with friends who smoke and previous smoking status were consistently associated with an adolescent's future smoking status. Other factors, such as attachment to father or to mother, parental supervision, extracurricular activity, perceived negative and positive effects of smoking, and academic involvement, were all related to late adolescent smoking status. These observations suggest that strategies that influence smoking behavior need to be directed not only to the individual child but also to influences within the child's home and school environment.