There has been an increase in the number of patients treated with pegylated interferon (PEG-IFN) and ribavirin due to the better antiviral efficacy. The main serious adverse events of PEG-IFN plus ribavirin combination therapy are bone marrow suppression and hemolytic anemia. However, there are few reports of vasculitis occurring during PEG-IFN therapy. We describe a patient who developed vasculitis during the treatment of chronic hepatitis C with PEG-IFN and ribavirin. (Korean J Hepatol 2007;13:419-422)