OBJECTIVE The present study examined the relationship between cigarette smoking and alcohol use outcomes over an 8-year period following treatment for adolescent alcohol and other drug (AOD) use disorders. METHODS The present study was based on a sample of 166 adolescents recruited during inpatient AOD abuse treatment. Included in this study were 123 (74% of the full sample) participants, of whom 41% were female, 81% identified themselves as White and who averaged 15.9 years of age (SD = 1.3) when entering treatment. Data for the present study were drawn from interviews conducted at the time of treatment and 2-, 4-, 6- and 8-years post-treatment. RESULTS Twenty six percent of participants had quit smoking for > 1 year at the 8-year assessment, while 44% reported persistent smoking over time. Overall smoking rates decreased significantly over time. Subjects associated with the highest alcohol involvement trajectory reported significantly greater likelihood of persistent smoking as well as higher current smoking and cigarette consumption across time points. CONCLUSIONS The significant declines observed in smoking from adolescence into young adulthood were contrary to expectations, indicating that this behaviour may be less stable than previously thought among adolescent AOD abusers. Smoking involvement over time was greater within the highest alcohol use trajectory, consistent with previous evidence for a positive relationship between these behaviours. However, when compared with the general population smoking rates remained very high regardless of alcohol involvement. Thus, individuals treated for AOD abuse as adolescents remained at elevated risk for tobacco related disease regardless of post-treatment AOD use outcomes.