A 42-year-old woman with chronic hepatitis C has visited our hospital since October 2003. Liver biopsy revealed chronic hepatitis (A1/F1) . Therapy was initiated with interferon (IFN) alpha-2b and ribavirin in February 2004. Two months later, the patient developed left facial weakness. Laboratory findings showed cryoglobulinemia and abnormal thyroid function without any evidence of other viral infections. Idiopathic peripheral facial nerve palsy was diagnosed. IFN was discontinued at week 9 of therapy, but she obtained sustained virological response and her symptoms resolved at 6 month after the withdrawal.