Post-transplant lymphoproliferative disorders (PTLD) are a rare but serious complication after organ transplantation. A French Registry of PTLD was set up in a nationwide population of kidney transplant recipients. We prospectively enrolled all adult kidney recipients developing PTLD between January 1, 1998, and December 31, 2003. We analyzed the incidence, risk and prognostic factors of PTLD by Kaplan-Meier and Cox analyses. Totally 230 cases of PTLD were referred to the French Registry. Cumulative incidence was 1.18% after 5 years. Older age (per year, AHR = 2.19, CI = 1.22-3.94) and recipient Epstein-Barr virus seronegativity (AHR = 3.01, CI = 1.57-5.08) were associated with an increased risk of PTLD. Patients with PTLD had a reduced survival rate (61% at 5 years). Graft PTLD had the best prognosis with an 81% survival rate after 5 years. Infection with hepatitis C or B virus (HCV or HBV), late-onset PTLD, multiple sites involvement and high Ann Arbor staging were risk factors for patient death. Use of azathioprine was associated with a poorer survival rate. PTLD incidence and risk factors in French recipients are in line with the international or American PTLD series. We highlighted the role of HBV or HCV in patient mortality and described the relevant prognosis factors for patients with post-transplant lymphoproliferations.