To analyse the barriers for anti-hepatitis C virus (anti-HCV) treatment in human immunodeficiency virus (HIV)-HCV coinfected patients, we surveyed 71 physicians specializing in infectious disease (39%), internal medicine (27%), HIV/AIDS information and care (17%), haematology (10%) and hepatology (6%). A standard data collection form was used to identify patients observed in 7 days in November 2004. Three hundred and eighty patients with the following characteristics were included: male gender 71%; mean age 41.5 years; HIV diagnosed 12 years ago; routes of transmission via injection drug use (78%); undetectable HIV viral load (235/373, 63%) or <10 000 copies/mL (86/373, 23%). HCV RNA was positive in 325 of 369 (88%) patients; HCV genotype was 1 or 4 in 65% and liver biopsy had been carried out in 56%. There were several explanations for the nontreatment of HCV in 205 of the 380 (54%) patients, with 2.4 reasons per patient: anti-HCV treatment was deemed questionable (n = 109) because of minor hepatic lesions, alcohol consumption, or active drug use; no liver biopsy had been performed (n = 68); treatment was contraindicated (n = 62), mainly for psychiatric reasons; there was physician conviction of poor patient compliance (n = 62) and patient refusal (n = 33). Patients having received anti-HCV treatment (n = 91) compared with those who had never received any (n = 205) were more commonly of European origin, had better control of their HIV infection, were followed by a hepatologist more often, had a liver biopsy more often and had more commonly a high HCV viral load (P < 0.001). In 'real life' in France in 2004, more than half of the HIV-HCV coinfected patients have never received anti-HCV treatment. The main reasons are a treatment that may be deemed questionable (minimal hepatic lesions, alcohol, active drug use), a lack of available liver biopsy, a psychiatric contraindication and physician conviction of poor patient compliance.