PURPOSE: Adolescents with substance use (SU) problems have high rates of tobacco use, yet SU treatment has historically ignored treatment for tobacco use. Barriers to such efforts include the belief that tobacco cessation could compromise other SU abstinence. This study examines self-initiated tobacco cessation and 12-month alcohol and drug abstinence in adolescents entering SU treatment in a private, managed care organization. RESULTS: Self-initiated tobacco cessation at 6 months, and at both 6 and 12 months, were related to higher odds of drug abstinence but not alcohol abstinence. CONCLUSION: Self-initiated tobacco cessation was not related to poor SU outcomes, and may be important to maintaining drug abstinence. Implementing tobacco cessation efforts in SU treatment can be challenging, but comprised SU outcomes may not be a barrier. The positive associations for drug abstinence and lack of associations for alcohol abstinence could be due to differences in motivation, medical conditions, or to the illicit nature of drug use. Tobacco use has serious long-term health consequences, and tobacco cessation efforts in adolescent SU treatment programs need further research.