OBJECTIVE Patients with human immunodeficiency virus (HIV) are also likely to be at risk for other infectious pathogens including hepatitis B(HBV) and C(HCV) viruses, which complicate the clinical course, management, and therapy. The literature on the prevalence of HBV/HCV coinfection with HIV in Iran is sparse. Hence this study was conducted to investigate this coinfection pattern and its risk factors in Isfahan, Iran. METHODS All of the HIV-infected patients attending clinics for acquired immune deficiency syndrome (AIDS) research and education in Isfahan province during the period of May 1998 through April 2007 were included in this cross-sectional study. After giving their informed consent, the patients were screened for hepatitis B surface antigen (HBsAg) and antibodies to hepatitis C virus (anti-HCV), and anti-HCV-positive cases were confirmed with the RIBA test. The demographic data and information about risk behaviors were collected as well. Multivariate logistic regression was used to identify independent risk factors for HBV and HCV. RESULTS The subjects included 130 patients (128 males and 2 females) with a mean age of 50.23 ± 8.81 years. Most of the subjects were unemployed (61.5%) and single (56.2%). A history of imprisonment, ,intravenous drug abuse, and high-risk sexual activity were reported by 83.7%, 83.5%, and 48% of the subjects, respectively. Coinfection with hepatitis viruses was observed in 78.5% of the subjects. Low levels of education, a history of imprisonment, and youth were the main risk factors for HCV/HIV coinfection (OR = 196, 114, and 0.9 respectively). CONCLUSIONS Our study showed that there is a high prevalence rate of HCV/HIV coinfection in Isfahan, Iran, with the major risk factor being a history of imprisonment.