OBJECTIVE: This study explored how HIV care differs for infected persons with and without severe mental illness. METHODS: Data were obtained through interviews with and chart review of 295 patients with severe mental illness and HIV from public mental health agencies in Los Angeles County and New York City. Data were compared with data from 1,294 HIV patients without severe mental illness from a separate national probability sample. Measures were difficulty obtaining care, whether patients recommend their HIV care provider, hospital problem score, functional health status, and disability days. RESULTS: In Los Angeles, HIV patients with severe mental illness were more likely than those without severe mental illness to have difficulty obtaining care (p