This study was done in order to evaluate the effectivity of combination therapy of standard interferon alpha (IFN-alpha) + ribavirin and pegylated IFN-alpha (PEG-IFN-alpha) + ribavirin in patients with chronic hepatitis C between 2003-2005 years in our clinic. Totally 52 patients were included in the study. In the combination treatment protocols, standard IFN-alpha 2 alpha or 2b plus ribavirin was given in 35 patients (group I) and PEG-IFN-a plus ribavirin in 17 patients (group II). Duration of treatment was 12 months. Rate of biochemical and virological responses at the end of the therapy and sustained response were 66.6%, 78.7%, 57.7% in group I and 71.4%, 85%, 66.7% in group II, respectively In conclusion, treatment protocols was effective in both groups and the rate of biochemical and virologic responses at the end of the therapy and sustained response were higher in group II than group I but the differences between groups were not significant. In according to the results of this study; PEG-IFN should be preferred to standard IFN-alpha.