Abstract: De Vlaamse ziekenhuisafdelingen zien zich vaak geconfronteerd met matige tot ernstige psychiatrische comorbiditeit, zoals delirium en agitatie, depressie en suïcidaliteit, psychotische stoornissen, anorexia nervosa met ernstig ondergewicht, intoxicaties en onttrekkingssyndromen, alsook gedragsproblemen van patiënten, zonder dat men de nodige expertise en uitrusting ter beschikking heeft. Niet minder dan 1/3 van de klinisch opgenomen patiënten lijdt aan psychiatrische comorbiditeit (1, 2). The medical-psychiatric unit (MPU) constitutes an important integrated health service for the diagnostic assessment and the treatment of patients with co-occurring somatic and psychiatric morbidity when the somatic problems are too complex for the psychiatric department or the psychiatric disorder complicates or prevents treatment at a medical ward. There are different types of MPU based on the level of acuity, as well as on the objectives and the service providing the actual care. As yet and in contrast to The Netherlands, the United States and many other countries, no similar combined health service is operational in Flanders (Belgium). With the aim to improve the quality of care in case of any such moderate to severe comorbidity and to ensure the safety of care and the staff, the authors deem it advisable to set up MPUs in Flemish general and/or university hospitals. Indisputably, any MPU is a challenging and multifaceted endeavour. Their efficiency and treatment outcomes require further research, most preferably studies evaluating views and findings obtained in clinical practice. Also, funding and management frameworks need to be developed to facilitate the organisation and operation of such complex care units.