Combination of PEG interferon and ribavirin is the standard treatment of chronic hepatitis C. Efficacy of this treatment has never been evaluated in HCV-HIV infected patients, who have previously been treated with a first line anti-HCV treatment. The purpose of the study is to evaluate the combination PEG interferon alfa2a-ribavirin in HIV-infected patients with chronic hepatitis C pretreated with interferon alone or interferon combined with ribavirin. The patients receive a dose of 180 µg of PEGASYS once a week and 800 to 1200 mg/day of ribavirin (according to weight) for 48 weeks. Primary outcome of the study is a sustained virological response, defined as an undetectable HCV RNA level 24 weeks after the end of anti-HCV treatment.