Chronic liver disease caused by hepatitis C virus (HCV) seems to present a more accelerated course in HIV-infected patients, leading to cirrhosis and liver failure in a shorter period of time than in HIV-negative individuals. As efforts to increase life expectancy in HIV-infected people progress, substantial morbidity and mortality from HCV infection is likely to arise amongst subjects infected parenterally, such as injecting drug users, haemophiliacs and transfusion recipients. Preliminary results have suggested that alpha-interferon (IFN) treatment allows higher rates of response in HIV-infected patients with higher CD4+ lymphocyte counts, suggesting a primary dependence of IFN on a preserved immune system in order to act appropriately. In an open, multicentre, prospective trial we analysed whether the use of larger doses of IFN, through an escalating schedule, might overcome the limits imposed by immune dysfunction. An interim analysis performed in 29 patients concluded that escalating the dosage did not improve the rate of response to IFN. In fact, only one (8.3%) out of 12 patients without response after 3 months of being on IFN therapy achieved response after the dosage was increased from 5 MU to 8 MU s.c. three times a week. Moreover, he relapsed 3 months after completion of treatment for 1 year.