Risk behaviors and health care use among 396 initially hospitalized veterans with severe mental illnesses were examined. Health care use was abstracted from Veterans Affairs databases (March 1998 to June 2000) for one year after hospital discharge. Lifetime intravenous drug use was related to increased use of outpatient services, and current alcohol use was related to decreased health care use. Patients with posttraumatic stress disorder had greater use of medical outpatient services than patients with schizophrenia-spectrum disorders, although they had longer hospital stays. These results highlight that veterans with severe mental illness receive more treatment in medical than psychiatric health clinics.