It was hypothesized that the presence of psychiatric disorders would be associated with allocation to detention with compulsory treatment. To test this hypothesis, incarcerated boys from detention regimens with and without compulsory treatment were compared with respect to psychiatric disorders and potential other allocation criteria, such as sociodemographics, crime-related characteristics, and treatment history. A cross-sectional study of a representative sample of incarcerated boys in the Netherlands aged 12 to 18 was conducted, using the Diagnostic Interview Schedule for Children (DISC). Data were collected from December 1998 to December 1999. Ninety percent of participants met the criteria for at least one psychiatric disorder. A high comorbidity rate (67 percent) was demonstrated. Only Dutch ethnicity and violent index offense proved to be independent predictors of treatment allocation. According to the DISC-C, 90 percent of the incarcerated boys suffered from at least one psychiatric disorder before arrest: disruptive behavior disorder 75 percent; substance use disorder 55 percent; psychotic symptoms 34 percent; ADHD 8 percent; anxiety disorder 9 percent; and affective disorder 6 percent. 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. Compared with North American studies, relatively low rates of anxiety and affective disorders were found. This may be due to the better availability of mental health services to disadvantaged youths with internalizing problems in the Netherlands. Future research should examine whether standardized psychiatric assessments can improve the efficiency of allocation to detention programs with or without psychiatric treatment options. 4 tables, 35 references