Background: The hepatitis C virus (HCV) is a blood born virus and the major cause of liver diseases worldwide. Distribution of HCV genotypes varies depending on geographical regions and routes of infection. Knowledge regarding the distribution of HCV genotypes and related risk factors plays an essential role in the control of HCV infection in the community. Objectives: The current study aimed at determining the current distribution of HCV genotypes and related risk factors among Iranian blood donors. Methods: In the current analytical, cross sectional study, 106 HCV-infected blood donors with detectable HCV RNA over the country were interviewed by trained physicians through a post-donation questionnaire on demographic, medical, and risk history from November 2015 to May 2017. The hepatitis C virus genotype was determined by sequencing of a segment of non-structural 5B region in HCV genome. Penalized logistic regression model was used for statistical analysis through STATA software. Results: Hepatitis C virus genotype was determined in all subjects, and the genotype 3a was the most frequent (65, 61.32%), followed by 1a (31, 29.25%), and 1b (10, 8.49%). Based on the multivariable analysis results, tattooing (adjusted odds ratio: 2.76; 95% confidence interval: 1.03 - 7.37) was associated with HCV genotype 3a. Conclusions: According to the results, it seems that changes in molecular epidemiology of HCV infection and replacement of HCV genotype 1a with 3a, characterized by an increase in genotype 3a and decrease in genotype 1a have occurred over the last decade among Iranian blood donors. Tattooing was an independent risk factor for HCV infection by genotype 3a.