Patients with end-stage renal disease are at high risk for exposure to hepatitis C virus (HCV) infection. Although both viral replication and liver disease progression are accelerated after renal transplantation (RTx), long term-impact of chronic HCV infection is unclear. Our aim was to detect the course of HCV infection in renal transplant recipients (RTR) and to detect the effect of HCV reactivation on patient and graft survival.We retrospectively analysed the 21 year (1985-2006) data of 1274 RTR, 43 of whom were anti-HCV positive at the time of RTx. HCV reactivation was defined as increase serum ALT, AST levels, HCV RNA positivity and/or chronic active hepatitis histological findings on liver biopsy. Thirty three (76.7%) and 10 (23.3%) of patients were male and female respectively. Mean age of patients at the time of transplantation was 33.0 ±1.7 years, mean follow up period after RTx was 62.0±7.3 month. At the time of RTx, HCV RNA was positive in 11 (25.6%) patients,it was negative in 32 (74.4%) patients. HCV reactivation was seen in 19 (45.2%) of patients at the mean time of 20.8±5.7months after RTx. In 31 (72%) patients, acute rejection occured, whereas chronic rejection of the graft kidney had occured in 10 (23%) patients. Three (7%) patients were died after RTx. Out of 43 patients, 22 (51.2%) of them were treated with standard interferon before RTx. There was statistical significance between pretransplant interferon theraphy and pretransplant HCVRNA level (p=0.024). There was no statistically significance between HCV reactivation and acute rejection, mortality and graft survival (P>0.05). HCV reactivation occurs in near half of RTR mostly in the second year after RTx. Patient survival and graft survival are not affected by HCV reactivation.