OBJECTIVE: Liver disease associated with hepatitis C virus (HCV) is a serious cause of mortality among people living with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) (PLWHA). Little is known about the HCV knowledge of PLWHA. METHODS: One hundred seventy-nine patients at an infectious disease clinic were interviewed on HCV knowledge and alcohol use. RESULTS: Sixty-six percent of participants indicated that HCV is transmitted through blood; 53% indicated that persons with HIV-HCV co-infection can benefit from HCV treatment; and 79% and 74%, respectively, indicated that safer sex and safer injection techniques can prevent HCV transmission. Among PLWHA with self-reported HCV, 97% indicated that persons with HCV should not drink alcohol, but 32% reported using alcohol in the past 30 days. CONCLUSIONS: Health education is needed to prevent HCV infections and increase HCV treatment-seeking. Higher education levels were related to more accurate HCV knowledge, indicating the need for health promotion for PLWHA of lower education levels.