Two hundred mentally ill adults receiving community-based outpatient psychiatric services were surveyed. Although 59% received an HIV test, only 41% received a hepatitis test. Clinic location and reports of unprotected sex were associated with receipt of an HIV test. Although no behavioral risk factors were associated with hepatitis testing, those with a comorbid medical condition were more likely to be tested. Only 15% of the sample was immunized against hepatitis B. Medical hospitalization was the only factor related to immunization. These results indicate an urgent need to improve access to HIV and hepatitis testing and related treatment.