Abstract : Introduction: Frequent transfusions in people with thalassemia put them at risk for the effects of increased iron load, leading to dysfunction of a number of organs such as the heart and endocrine glands including the liver and pancreas in these patients. Therefore, the aim of this study was to investigate the rate of pancreatic dysfunction in non-diabetic patients with thalassemia major. Materials and Methods: This study was a group of historical study. Forty patients with non-diabetic thalassemia major (case group) and 40 healthy children based on age and BMI were included and for both groups, the Oral Glucose Tolerance Test (OGTT) was concluded; glucose, fasting insulin, C-peptide levels, Serum ferritin, and plasma sugar were measured two hours after receiving glucose. The insulin resistance index (HOMA IR) and beta-cell function index (HOMA-B) were calculated based on the evaluation model (HOMA). SPSS software version 20 and SAS version 9.1 were used for statistical analysis of the data. Results: average fasting blood glucose (P = 0.050), insulin (P <0.001), C-peptide (P <0.001) as well as insulin resistance index (P <0.001) and beta-cell function index (P <0.001) in the case group was significantly higher. According to the OGTT test, none of the individuals in the case-control groups had diabetes, the prevalence (IGT) in the case group and control was 22.5% and 2.5%, respectively, which were significantly higher in the case group (P = 0.007). According to the following analys