Objective : This study is subjected to estimate serum Leptin level in Egyptian thalassemic patients and to evaluate its correlation with different clinical data including age, sex, growth parameters and pubertal stage. Methodology: serum leptin level was estimated using IRM (Immunoradiometric assay in thirty patients with thalassemia major besides ten healthy controls. Results: Results of the study were analyzed by appropriate statiscal methods. Our results revealed that serum leptin levels were significantly lower in thalassemic patients than in the normal age and sex matched controls indicating that adipose tissue is affected by iron overload as a part of the end endocrinological dysfunction detected in thalassemia major. Male cases expressed significantly lower leptin levels than both female cases and normal controls. Weight, height and BMI were estimated and correlated with leptin levels denoting that BMI and weight showed a significant correlation with leptin levels in both cases and controls. Conclusion: Reduced serum level of leptin in Egyptian thalassemic patients. Leptin deficiency proved to be a cofactor in the development of endocrinological disturbances in thalassemics.