Several studies suggested that the incidence of new-onset diabetes following pediatric kidney transplantation has increased markedly in recent years, with reported incidence of up to 20%. However, limited information is available regarding the incidence and features of pretransplant status of abnormal glucose tolerance in pediatric kidney transplant recipients. We assessed the risk of 55 non-diabetic pediatric transplant recipients developing PTDM by performing OGTT prior to transplantation. For post-transplant immunosuppression, each patient received either a CsA- or a TAC-based regimen. However, recipients who had abnormal glucose tolerance in the pretransplant OGTT were allocated to the CsA-based regimen. The mean age of the patients was 9.7 +/- 5.4 yr while mean BMI was 16.5 +/- 3.3 kg/m2. FPG level before transplantation was within the normal limit in all patients, while the mean HbA1C value was 4.5. However, 18 of the 55 patients (32.7%) had abnormal glucose tolerance in the pretransplant OGTT, 13 (23.6%) had impaired glucose tolerance, and 5 (9.4%) had DM. PTDM developed in two patients on the TAC-based regimen with these patients having normal glucose tolerance prior to the transplant. In contrast, the 18 patients with abnormal glucose tolerance did not develop PTDM under CsA-based immunosuppression. Our results demonstrated an unexpectedly high prevalence of abnormal glucose tolerance in pretransplant OGTT even in a pediatric population. We believe that modification of post-transplant immunosuppression by the identification of high-risk patients using the pretransplant OGTT may minimize the development of new onset of PTDM.