Objective: To determine the prevalence of psychiatric disorders among incarcerated male adolescents and to investigate the influence of psychopathology on allocation to either plain detention or detention with compulsory treatment. Method: A cross-sectional study of a representative sample (N = 204) of incarcerated boys aged 12 to 18, using the Diagnostic Interview Schedule for Children (DISC). Data were collected from December 1998 to December 1999. Results: Of the eligible subjects, 79% agreed to participate. Ninety percent reported at least one psychiatric disorder: disruptive behavior disorder 75% (95% confidence interval [CI]: 68-81%), substance use disorder 55% (95% CI: 48-63%), psychotic symptoms 34% (95% CI: 27-41%), ADHD 8% (95% CI: 5-13%), anxiety disorder 9% (95% CI: 6-15%), and affective disorder 6% (95% CI: 3-10%). After controlling for a broad range of sociodemographic characteristics and former treatment parameters, the presence of a psychiatric disorder was not associated with allocation to compulsory treatment. Conclusions: Compared with North American studies, relatively low rates of anxiety and affective disorders were found, probably due to the better availability of mental health services to disadvantaged youths with internalizing problems in the Netherlands. It should be examined whether standardized psychiatric assessments can improve the efficiency of allocation to detention programs with or without psychiatric treatment options.