BACKGROUND: Histological recurrence of the hepatitis C virus (HCV) occurs in the majority of persons transplanted for cirrhosis as a result of HCV. Herein we analyze our experience with the use of both conventional and pegylated (PEG) interferon (IFN) in combination with ribavirin (RBV) in liver transplant recipients with recurrent HCV. Methods: Patients transplanted between 1992 and 2001 with post-orthotopic liver transplantation (OLT) histological recurrence of HCV, and who were treated with at least 6 months of IFN or PEG-IFN in combination with RBV were included in this analysis. A retrospective chart review was performed. Results: A total of 31 patients were included. Fifteen were treated with IFN/RBV and 16 with PEG-IFN/RBV. Of these 16, 11 had been begun on IFN/RBV and were changed to PEG-IFN/RBV because of persistent viremia. Three patients (20%) in the IFN/RBV group and six patients (37.5%) in the PEG-IFN/RBV group experienced a virologic response (VR) on therapy. Of the six patients experiencing VR in the PEG-IFN/RBV group, three (50%) were IFN/RBV non-responders. There were two sustained VRs (SVR). The 65.6% of all patients experienced a biochemical response (BR) on therapy. Seven deaths were observed. Dose modifications of IFN or PEG-IFN (87.1%) and RBV (80.6%) and the requirement for hematopoietic growth factors were frequent. Conclusions: Treatment of recurrent HCV infection with combination of IFN or PEG-IFN and RBV produced an on-therapy VR in 29% and BR in 65% of patients. Hematologic toxicity and dose modifications were frequent. Our experience with antiviral therapy for HCV post-OLT remains disappointing but PEG-IFN + RBV appears to produce VR in a sizable portion of IFN + RBV non-responders.