Background/Aim. The most important ethiology factor of chronic liver disease that progresses into terminal insufficiency is hepatitis C virus (HCV) infection. Intravenous (iv) drug abuse is the main cause for spreading HCV. Thus the therapy for such patients is of extreme importance in reducing the incidence of the disease. The aim of the study was to establish efficacy of a combined therapy with peginterferon alpha-2a and ribavirin in iv opiate substances abusers having chronic HCV infection in relation to sex, age, genotype and level of fibrosis and duration of HCV infection before the treatment. Methods. Thirty one iv opiate substances abusers with chronic hepatitis C (HHC) were enrolled in the examination. The patients were divided according to the genotype into two groups. The patients with genotypes 1 and 4 (n = 18) were treated for 48 weeks, while those with genotypes 2 and 3 (n = 13) for 24 weeks. PCR HCV RNA, genotype determination and liver biopsy were done to each patient. Results. A stabile virological response was achieved in 93.5% of the patients, so the therapy demonstrated statistically significant efficacy i. v. opiate substances abusers with HHC (p < 0.001). There was no statistically significant difference in therapeutic response among patient groups formed according to the genotype, sex, duration of the disease and level of fibrosis (p > 0.05). Conclusion. Therapy of of iv opiate substances abusers with HHC has its specificities, and these patients need special treatment. Efficacy of the therapy was equivalent in patient groups formed according to the sex, genotype, level of fibrosis and duration of HCV infection. A combined therapy with peginterferon alfa 2a and ribavirin has high level of success in the treatment of these patients.