nearly all the data on the efficacy of combined antiviral therapy on chronic hepatitis C genotype 4 have been obtained in countries of Middle East. Genotype 4 is quite unusual in Spain. We report our experience in a group of Spanish patients treated with homogeneous criteria.between 2001 and 2007 we have treated 30 patients with chronic hepatitis C genotype 4 (20 males) with pegylated Interferon alpha-2b (26 cases) or alpha-2a (4 cases) combined with ribavirin at a weight-adjusted dose. Results of therapy are known in all patients and liver biopsy is available in 24 cases.ten patients (33.3%) obtained sustained viral response (SVR: HCV-RNA undetectable in blood 6 months after the end of therapy), 12 were primary non-responders, 4 relapsed after reaching undetectable HCV-RNA at the end of therapy and 4 interrupted the treatment due to severe adverse events. These results are very close to those obtained in 355 patients infected with HCV genotype 1.HCV genotype 4 should be considered as "difficult to treat". The better results of therapy in other geographical areas (Middle East) may be due to a different distribution of the subtypes of HCV genotype 4.