Today hepatitis C is one of the unsolved medical problems and results in a significant number of deaths in the HIV population, particularly in southern Europe and the USA, where the prevalence of HCV/HIV-coinfection in the HIV population ranges from 30-50%. Recent trials using pegylated interferon alfa in combination with low dose ribavirin have achieved overall sustained response rates of up to 42%. However, high discontinuation rates, adverse events associated with mitochondrial toxicities or treatment of patients with advanced cirrhosis may decrease response to treatment and result in serious adverse events. Optimizing antiretroviral therapy before the start of interferon-based therapy and active management of adverse events will reduce complications and improve treatment success. The use of higher ribavirin doses and longer treatment periods should be systematically studied to improve hepatitis C therapy in coinfected patients in the near future.