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, the long-term impact of chronic HCV infection is unclear. Our aim was to analyze the course of HCV infection in renal transplant recipients and the effects of HCV reactivation on patient and graft survival. METHODS We retrospectively examined the 21-year (1985-2006) data of 1274 renal transplant recipients, 43 of whom were anti-HCV positive at the time of transplantation. RESULTS The mean posttransplant follow-up of 43 patients was 62.0 +/- 7.3 months. At the time of transplantation, HCV RNA was positive in 11 (25.6%) patients and negative in 32 (74.4%) patients. HCV reactivation was seen in 19 (45.2%) patients at a mean time of 20.8 +/- 5.7 months. In 31 (72%) patients, acute rejection occurred, whereas graft loss occurred in 10 (23%) patients. Three (7%) patients died. Among 43 patients, 22 (51.2%) were treated with interferon before transplantation. There was a statistically significant association between pretransplant interferon therapy and pretransplant HCVRNA level (P=.024), but no significant association of HCV reactivation and graft rejection, mortality, or kidney survival. CONCLUSIONS HCV reactivation occurred in nearly half of the renal transplant recipients, mostly in the second year. Patient survival and graft survival were not affected by HCV reactivation. Anti-HCV positivity should not preclude chronic renal failure patients from renal transplantation.