BACKGROUND : This study investigates the frequency of psychiatric disorders and the sociodemographic and clinical features in adolescent prisoners. METHODS : The psychiatric diagnoses and sociodemographic characteristics of treatment of 76 adolescent male prisoners and 76 age-matched patients were compared (age range: 15-17). RESULTS : Conduct disorder (85.5%), attention deficit hyperactivity disorder (61.8%), depression (50%), substance abuse (40.8%), post-traumatic stress disorder (19.7%), and psychotic disorder (3.9%) were more frequent among adolescent prisoners than the control group. The educational levels of parents of adolescent prisoners and their socioeconomic statuses were significantly lower, and the nonsuicidal self-injury (73.7%) and tattooing frequency (65.8%) were significantly higher among adolescent prisoners than the control group. Only 51.3% had both parents living together. CONCLUSIONS : Psychiatric disorders, low socioeconomic status, family disorganization, nonsuicidal self-injury, tattoos, and interruption of education were frequent in adolescent prisoners in this study. Our findings emphasize the importance of early psychiatric treatment and family-based interventions to help prevent adolescents from committing crimes. In addition, nonsuicidal self-injury and tattoos may be associated with criminal behavior in adolescents.