Post-transplantation lymphoproliferative disorder (PTLD) is a rare but devastating and often fatal complication that occurs in renal transplant recipients. We enrolled PTLD occurring in 7450 kidney recipients at 5 transplantation centers from 1984 to 2008 to assess the incidence, clinical features at presentation, clinical outcome, response to treatment, patient and graft survival ,and risk factors for early-onset (< 1 year) versus late-onset (> 1 year) PTLD. Baseline immunosuppression consisted cyclosporine, mycophenolate mofetil (MMF)/AZA and prednisolon + /_ anti lymphocyte globulin (ALG). Of the 7450 patients (51.3% male), 39 (0.52%) who developed PTLD with the mean age of 40 (19-66) years. Early and late PTLDs were developed in 9 and 27 recipients, respectively. There were no statistically significant differences between the two groups in terms of sex, age, immunosuppression with anti lymphocyte globulin (ALG), acute rejection, patient and allograft survival, CMV infection and response to therapy. Hodgkin lymphoma was only seen in two cases with late PTLD. One year patient survival, from the diagnosis of PTLD, was 60% and 61% in early and late PTLD groups, respectively. There was significant correlation between immunosuppression regimen and occurrence PTLD (i.e. MMF was predominated in early PTLD patients). Although early-onset PTLD have been frequently reported a favorable outcome, our study showed that early and late-onset PTLD have the same outcome.