Patients with both psychiatric and medical illnesses present complex and, at times, difficult diagnostic and management problems. Medical-psychiatric units designed to provide integrated medical and psychiatric care have been established in the United States. This paper describes the development and structure of such a unit established at a Canadian general hospital, using psychiatric facilities and resources already in place. A one year review of the characteristics of patients discharged from the service found that their mean length of stay was similar to that of inpatients discharged from the general adult inpatient services, but shorter than that of patients discharged from the psychogeriatric service. Many of these patients had neurological conditions; coexisting affective disorders, substance abuse, organic mental syndromes and somatoform disorders were diagnosed frequently. We believe that a medical-psychiatric inpatient unit can provide integrated care to patients who might otherwise receive less than adequate care.