OBJECTIVES: Complications are common following kidney transplantation. The French Hospital National Database (PMSI) allows patients follow-up through their hospitalization reports. This study assessed 4-year incidences of complications after kidney transplantation and estimated their economic impact, in particular renal complications. METHODS: From the years 2006-2010, hospitalization data for all patients with kidney transplantation in year 2006 were extracted. Patients’ hospital stays were followed during a period of 4 years. Major hospitalizations of interests were pooled in renal, cardiovascular and infectious complications. Renal complications were detailed in graft loss, acute renal insufficiency (ARI), acute rejection (AR), recurrence of initial nephropathy (RIN), chirurgical complication and, others. Incremental costs were estimated by subtracting transplantation-year mean cost of patients without any renal complications to the one of those with renal complications the same year. Mean annual costs of patients with graft loss were assessed separately for each year. Costs were calculated according to the 2010 National Hospital Tariff and National Scale. RESULTS: A total of 2392 patients with kidney transplantation in 2006 were identified. A total of 61.5% were males and mean age was 45.0(±14.9) years old. 4-year cumulative incidences of renal, cardiovascular and infectious complications were 54.8% (n=1,311), 20.8% (n=498) and 19.8% (n=474). Incidences of ARI, AR, RNI, chirurgical complication and, others renal complications were 24.5%, 21.1%, 4.1%, 3.1% and 22.4%, respectively. Compared to other patients without any renal complication (First-year mean costs: €25,170; Q1:€17,341–Q3:€27,649), the corresponding incremental costs for renal complications were €7,046, €10,376, €10,238, €7,874 and, €5,668. During the 4-year period, graft loss occurred in 4.4% patients. Annual mean costs of graft loss for the first, second, third and fourth years were €32,159 (Q1:€11 723–Q3:€41,890) (n=105), €19,085 (n=64), €25,269 (n=52) and, €20,780 (n=41), respectively. CONCLUSIONS: After transplantation, short-term renal complications are frequent and expensive. Intensive interventions on renal preservation and graft loss prevention are needed.