OBJECTIVE: To increase understanding of the needs of elderly patients with serious mental illness, the study analyzed and compared use of hospital-based services by geriatric patients with bipolar disorder and schizophrenia. METHODS: The sample consisted of 23 patients with bipolar disorder and 49 patients with schizophrenia age 65 or older admitted to the Cleveland Veterans Affairs Medical Center over a two- year period. Patients' charts were reviewed to assess psychiatric and medical hospitalizations over the past ten years. Comorbid medical diagnoses, prescription patterns, and competency status were also reviewed. RESULTS: Patients in both diagnostic groups used inpatient services relatively frequently, with a mean of four hospitalizations in ten years. Length of stay among patients with schizophrenia (mean = 58.2 days) was almost twice as long as that of patients with bipolar disorder. Hospitalization for medical reasons was infrequent. Mood- stabilizing medications, usually lithium, were prescribed to most patients with bipolar disorder, and antipsychotics were prescribed to most patients with schizophrenia and less than half of the patients with bipolar disorder. More than half of the patients with schizophrenia had legal guardians, but few patients with bipolar disorder did so. CONCLUSIONS: Findings of this and other studies suggest that although the prognosis for persons with serious mental illnesses may have improved over the last several decades, these illnesses do not "burn out" in older adults. Elderly patients continue to make frequent use of inpatient psychiatric hospitalization and pharmacological interventions.