Purpose: To investigate overall characteristics of glucose intolerance in survivors from childhood hematologic disorders and evaluate potential risk factors of developing diabetes mellitus (DM) Methods: Clinically indicated retrospective review from 14 children who developed either diabetes or prediabetes after diagnosed with hematologic disorders were performed. Data were analyzed according to baseline characteristics of the patients, diabetes profiles, and undergone treatment including hematopoietic stem cell transplantation (HSCT). HbA1c cutoff for diabetes mellitus and prediabetes was defined as above 6.5 % and between 5.7-6.3 %, respectively. Results: Among 14 children, 7 (50.0 %) were diagnosed with leukemia and 7 with aplastic anemia; median age at diagnosis was 8.3 years (0.66 - 14.8). 8 patients (57.1 %) were diabetic whereas 6 (42.9 %) were prediabetic; median time interval from diagnosis of underlying disease to glucose intolerance was 5.4 years (0.7 – 10.1) and HbA1c at diagnosis of glucose intolerance was and 6.6 % (5.7 – 9.4). 12 patients (85.7 %) underwent HSCT with administration of various chemotherapeutic agents (including steroid), total body irradiation (28.5 %) and red blood cell (RBC) transfusion (100.0 %). In regression analysis, initial HbA1c, fasting blood glucose and amount of RBC transfusion were positively correlated with HbA1c elevation while glucocorticoid dose (R2=0.920, P=0.019) was suggested as a strong risk factor for glucose intolerance for both leukemia and aplastic anemia children. Using a receiver operating characteristic (ROC) curve, potential cutoff dose glucocorticoid for the diagnosis of diabetes was 6232 mg (area under curve=0.990, p=0.02). Conclusion: In young survivors after completion of leukemia treatment, several clinical and biochemical factors could influence HbA1c level and impair glucose intolerance while glucocorticoid dose may be a trigger factor for newly diagnosed diabetes.