Interferon treatment of hepatitis C virus (HCV) infection in transplant recipients carries a high risk of rejection. We treated these patients with ultralow-dose interferon-alpha (1 x 10 units subcutaneously three times/week) plus ribavirin (600 mg/day) for 48 weeks. Treatment efficacy was evaluated by the changes of serum liver enzymes and viral load. A total of 11 patients were recruited for the study; biochemical response was obtained in all patients but one. Three patients terminated the therapy prematurely because of acute graft failure (one case) and urosepsis (two cases). Of the eight patients who completed a full course of therapy, five cleared HCV RNA at the end of treatment. Sustained biochemical and virologic responses were obtained in three patients (37.5%). Our regimen seemed to be relatively safe for renal transplant recipients with HCV. A significant portion of patients may achieve sustained biochemical and virologic responses.