The authors investigated the relation between psychopathology in medically ill inpatients and use and cost of medical care services. Of 455 medical inpatients, the Medical Inpatient Screening Test identified 27.9% as very depressed, 27.5% as very anxious, 20.2% as having cognitive dysfunction, and 8.6% as having high pain levels. Overall, the test identified 51% of the patients as having high levels of psychopathology or pain. These subjects had a 40% longer median length of hospital stay and 35% greater mean hospital costs than those with low levels of psychopathology or pain. Patients with greater psychopathology also had higher hospital charges, more procedures during hospitalization, and more discharge diagnoses but did not differ from the other patients in sex, race, age, diagnosis-related group (DRG) major diagnostic category, or DRG weight.