The aim of the study was to assess the efficacy and safety of treatment with interferon alpha and ribavirin in patients with chronic hepatitis C and extrahepatic manifestations as well as to determine prognostic factors of therapy effectiveness. 179 consecutive naive patients with chronic hepatitis C treated with interferon alpha and ribavirin were studied. 120 patients (67%) presented extrahepatic manifestations. The most frequent were cryoglobulinaemia, thrombocytopenia and thyroid gland pathology. Efficacy of antiviral treatment was lower (SVR 33.3% vs. 52.5%, p=0.013) and frequency of adverse events higher in patients with chronic hepatitis C and extrahepatic manifestations in comparison to those without extrahepatic pathology. Younger age, shorter duration of HCV infection and less advanced liver fibrosis were prognostic factors of better response to antiviral therapy in group of patients with chronic hepatitis C and extrahepatic manifestations.