Objective: The primary objective of this study was to investigate if among medical inpatients their health service use was associated with 1) presence and type of mental disorders, 2) emotional distress and somatization, 3) self-rated physical disability and health. Method: Health service use (number of admissions to nonpsychiatric departments and reimbursement of primary care services) as well as psychological distress (SCL-8D) and somatization (Whiteley-7) was assessed for 294 consecutive medical inpatients. Patients rated their own health and physical functioning, and medical consultants assessed them for chronic and life-threatening diseases. A subsample of 157 patients was assessed for ICD-10 psychiatric diagnoses by means of an extensive semistructured interview (SCAN). Results: High use (above 80th percentile) of inpatient admissions was statistically significantly associated to mental disorders (adjusted OR = 3.6 [95%CI, 1.3-9.7]), to anxiety and/or depression, somatoform disorders, chronic and life-threatening physical disease, severe (self-rated) physical disability, and SCL-8 and Whiteley-7 scores. High use of primary care was statistically significantly associated to mental disorders (OR = 3.4 [95%CI, 1.5-8.0]), to anxiety and/or depression, somatoform disorders, moderate or severe (self-rated) physical disability, fair, poor or very poor (self-rated) health, and the Whiteley-7 score. The SCL-8D score was significant in men only. Conclusion: Mentally disordered medical inpatients use health care more heavily than patients without, also after adjustment for medical disease severity. Use is closely associated to the Whiteley-7 and the SCL-8D.