Objective One of the spearheads of psychiatric healthcare in the Netherlands is hospital care for patients with a psychiatric comorbidity. In 2014, the Netherlands Psychiatric Association published ten field standards for Medical Psychiatric Units (MPUs). We catalogued healthcare in the Netherlands on the basis of these field standards. Design Telephone screening, followed by a questionnaire investigation. Method In the period MayAugust 2015, psychiatrists in 90 hospitals in the Netherlands were approached by telephone with 4 screening questions. If the department complied with the screening criteria for an MPU, a structured interview comprising 51 questions followed. The interview script was tested against the field standards using the Delphi method. Results The screening identified 40 potential MPUs; 37 (92.5%) wards participated in the complete interview. MPU care is unevenly distributed across the country. None of the MPUs complied with all field standards, even if the score on subcriteria concerning care content was relatively good. The main shortcomings were: lack of care facilities (predominantly somatic care facilities); no availability of continuous somatic nursing expertise; insufficient knowledge among somatic medical specialists of psychiatric care needs and lack of care chain arrangements. Conclusion MPUs are unevenly distributed across the country; care content is adequate, but education, tighter multidisciplinary cooperation and availability of somatic nursing expertise on every shift could improve care on MPUs. The departments should also pay more attention to care chain arrangements. The field standards are too stringent; these could be improved by defining 'essential care' and application of differentiated assessment of subcriteria.