Objective Black and ethnic minorities (BME) are disproportionally represented in western prisons and forensic psychiatric facilities. The authors wished to determine whether patient-related or services-related factors account for this overrepresentation. This study examined the relationship among the assessments of psychological accountability for a crime, treatment recommendations, and ethnicity among persons accused of a crime and suspected of having a mental disorder. Method We examined all 21,857 pre-trial psychiatric reports requested by Dutch courts between 2000 and 2006. Ethnicity was classified as Dutch native (n = 15,004), Black and minority ethnic (BME) groups (n = 6202), and Whites from other western countries (n = 638). Accountability assessments and treatment recommendations were compared using chi-square tests and logistic regression models, adjusted for demographic, psychiatric, and judiciary characteristics. Results Among BME and Whites from other western countries, accountability for the crimes committed was more often judged to be at the extreme ends of the spectrum, that is, “fully responsible” or “not responsible.” Compulsory admission to a psychiatric hospital was more frequently recommended for BME persons (OR: 1.38, 95% CI: 1.16–1.64) and Whites from other western countries (OR: 1.54, 95% CI: 1.05–2.27), but not admission to a penitentiary hospital or use of medication. The compulsory admission findings are largely explained by a higher prevalence of psychotic disorders in BME persons (19.8%) and Whites from other western countries (19.3%) as compared to Dutch natives (9.2%). Outpatient treatment was less often recommended for BME persons (OR: 0.81, 95% CI: 0.76–0.87) and Whites from other western countries (OR: 0.83, 95% CI: 0.70–0.99) than for Dutch natives. Conclusion Both patient-related and services-related factors play a role in the increased admission of BME groups and Whites from other western countries to psychiatric hospitals.