The rate of fibrosis progression was analyzed in 28 hepatitis C virus-infected liver graft recipients showing sustained virologic response after treatment with ribavirin plus either standard interferon alpha-2b (n=8), pegylated interferon alpha-2b (n=8), or pegylated interferon alpha-2a (n=12). Protocol biopsies before treatment as well as one, three, and five years after treatment showed no significant increase in mean fibrosis scores within the first three years after treatment (mean score at baseline 1.8 and at one and three years 2.0 and 2.1, respectively). Five years after cessation of treatment, the mean fibrosis score declined to 1.4 (P=0.2). Six of 28 patients (21%) showed an increase in fibrosis, five (18%) a decrease, and 17 (60%) no changes. The yearly fibrosis progression rate was 0.75 before treatment and 0.15 after antiviral treatment. Sustained virologic response is associated with a deceleration of fibrosis progression and might therefore play a major role in prevention of graft cirrhosis in hepatitis C virus-infected liver graft recipients.