Beta-thalassemia patients have high prevalence for HCV infection. In developing countries, HCV antibody is reported to be high in this group of patients. This study carried out to determine the distribution of HCV genotypes amongst the beta-thalassemia patients in North of Iran. The present study has been carried out between February and March 2010 amongst a group of 245 beta-thalassemia patients (125 male and 120 female) referred to the hospitals Mazandaran and Guilan provinces for a blood transfusion. Qualitative analysis of these samples using ELISA and PCR. The PCR positive samples were subjected to genotyping by RFLP method. Of total 245 beta-thalassemia patients who were the subjects of this study, 28 of these patients were diagnosed through PCR test to have RNA virus. For this reason, the prevalence of this illness in this study group was estimated as 11.42%. By using the RFLP technique, the above genotyping were identified and the prevalence of three genotypes, including 3a, 1a and 1b were proved. The genotype 3a was most prevalent. Out of 28 positive samples, 18 (64.3%) samples had this genotype. After that, genotype 1a with 9 positive occurrences (32.1%) and genotype 1b with only 1 positive occurrence (3.6%) were most prevalent. This study demonstrated that the main reason the beta-thalassemia patients became infected with the genotype of the virus was due to receiving infected blood that entered into Iran during the past two decades.