The adolescent drug problem places a huge toll on society and a heavy burden on the criminal justice system. Research regarding the benefits of therapeutic community (TC) treatment for adolescents has shown it to be effective. Despite the ability of therapeutic communities to lower drug relapse and reduce criminality, a great deal remains unknown in terms of how the process of treatment actually works for adolescents. Using data collected as part of the Drug Abuse Treatment Outcomes Study-Adolescent, this study examines the relationship between therapeutic engagement and treatment retention. The primary findings are that measures of therapeutic engagement had a significant association with whether or not an adolescent completed treatment. Findings suggest that instruments that evaluate therapeutic engagement are important in assessing involvement in treatment, and that programming designed to engage the adolescent in TC treatment should be utilized in order to reduce the risk of premature treatment dropout.