This application is in response to PA-03-126, "Behavioral Therapies Development Program." Research efforts to affect adolescent smoking cessation have not focused on detained teens. This is an opportune time to enhance interest in smoking cessation and subsequent quit rates. In addition, little is known about mechanisms of smoking cessation in adolescents, generally. The long-term objective of this research is to increase our understanding of effective smoking interventions for understudied adolescents at high risk for continued smoking into adulthood. This randomized clinical trial will use a 2 x 2 between groups design to investigate Motivational Interviewing (Ml) vs Relaxation Training (RT), and Cognitive Behavior Therapy (CBT) vs Self-Help Programming (SHP). Treatments are provided during brief stay in detention and adolescents are followed after release. We seek to increase quit rates post-release, and we will examine the moderating and mediating effects of motivation, anger, and self-efficacy. We will study main effects for treatment as well as whether the combination of MI/CBT is more effective than other treatments in enhancing quit rates. Frequently, treatment for smoking cessation is unavailable to youths in the juvenile justice system, and when treatment is available, it may be provided using untested therapies. This study extends previous research by rigorously evaluating smoking cessation interventions specifically for teens at highest risk for continued smoking in adulthood. We will examine processes contributing to the efficacy of treatments. The development of effective smoking interventions for juvenile detainees has the potential to reduce a significant public health concern in this underserved and high-risk population.