AbstractBackground: Beta thalassemia is a hereditary blood dis-order with defective beta chain formation. s-thalassemia is a major public health problem in Egypt. Patients with multi-transfused thalassemia develop severe endocrine complications due to iron overload.Aim of the Work: Was to study serum leptin in children with beta thalassemia and its correlation with iron overload.Subjects and Methods: The current study included 30 patients with beta thalassemia under treatment and follow-up in Hematology Unit, Pediatrics Department, Tanta University Hospital. All studied children were subjected to complete history taking, thorough clinical examination and laboratory investigations including complete blood count, serum iron, TIBC, serum glucose, serum ferritin and serum leptin using ELISA.Results: There were significant differences between pa-tients and control group as regard BMI and Tanner staging with delayed puberty according to Tanner staging and signif-icantly lower BMI in patients compared with controls. Signif-icantly higher levels of serum ferritin and serum iron and significantly lower TIBC were found in patients compared to control group. Serum leptin was significantly lower in patients than controls. There was significant positive correlation between serum leptin and age in studied patients and signifi-cantly higher serum leptin in female patients compared with males. Significant negative correlation was found between serum leptin and serum ferritin, but non-significant negative correlation between serum leptin and BMI.Conclusion: Decreased serum leptin in s-thalassemia patients with significant positive correlation with age with higher levels in females compared to males. There is significant negative correlation between serum ferritin and serum leptin.