Relatively little is known about the substance abuse treatment need patterns and experiences of youth incarcerated in the United States juvenile justice system. To address this issue, four analytic questions concerned with understanding the predictors of treatment need and utilization patterns among adolescents entering the juvenile corrections system are examined. Data analyzed were collected as part of a face-to-face survey of 401 youth who entered the Illinois juvenile correctional system in mid-2000. Overall, need for treatment and treatment utilization each were predicted by sets of social environmental and personal characteristics, in addition to several sociodemographic variables. Less than half of youth with an identified need for treatment reported receiving treatment. Considerable variability in the effects of demographic and social environmental indicators on treatment need and utilization across race groups also was observed. These findings underscore the need for the continual development of the cultural competence of treatment providers and the expansion of on-site provision of substance abuse treatment services to incarcerated juveniles.