Objectives: The prevalence of hepatitis C virus (HCV) infection in Sweden is estimated to 0.5%. Before 1992, blood transfusion posed a risk of HCV transmission. The primary aim of this study was to estimate anti-HCV prevalence in Stockholm County among individuals receiving blood transfusions 1965-1991. The secondary aim was to study the effect of age at transfusion on the development of liver disease and treatment outcome. Materials and methods: This is a retrospective analysis of individuals found to be anti-HCV tested positive in Stockholm County during a national screening campaign in Sweden 2008-2010. All anti-HCV-positive individuals were also HCV RNA tested. Data on age at transfusion, age at diagnosis, HCV genotype, viral load, fibrosis score, liver histology and antiviral treatment were recorded. Results: Out of 7473, 134 (1.8%) tested individuals were anti-HCV positive and 102 were HCV RNA positive resulting in a prevalence of chronic hepatitis C (CHC) of 1.4%. The rate of advanced liver damage was 18% (10/56). Patients younger than 19 years of age at transfusion were significantly more often started on antiviral treatment compared to adult patients, 65% vs 29% p < .001. No significant correlation was found between treatment outcome and gender or age at transfusion. Conclusions: In this study, we found an anti-HCV prevalence of 1.8% which is considerably higher than the estimated prevalence in the Swedish general population (0.5%), and patients infected during childhood were more likely to receive antiviral treatment. Additional data on the HCV epidemic in Sweden are needed regarding prevalence and age distribution.