Background and objective: In β-thalassemia, profound anemia and severe hemosiderosis cause functional and physiological abnormalities in various organ systems. In recent years, there have been few published studies mainly in adult demonstrating renal involvement in β-thalassemia. This case control study was aimed to investigate renal involvement in pediatric patients with transfusion dependant beta-thalassemia major, using both conventional and early markers of golmerular dysfunction, and to correlate findings to oxidative stress and iron chelation therapy. Methods: Sixty Beta-thalassemia patients (aged 4-18) and 20 healthy controls (aged 4-11) were enrolled in this study. Based age of presentation and frequency of blood transfusion patients were divided into two groups: group (A) 43 β-thalassemia major and group (B) 17 β-thalassemia intermedia. We measured level of creatinine, BUN, A/C, GFR using Schwartez formula and creatinine clearance and also serum Cystatin C was measured by immunosorbent assay (ELISA). Results: In Beta-thalassemia patients with and without chelation therapy glomerular dysfunction (13.3% had GFR<89 ml/min/1.73m²,47% had A/C >0.2 mg/dl and 40% had Cystatin C >1257 ng/ml) were reported. The only significant positive correlation was between A/C and serum ferritin in age group >6years .no correlation of Cystatin C with age, duration of the disease serum ferritin and A/C. Conclusion: Our data confirm presence of glomerular dysfunction in Beta-thalassemia pediatric patients which could be attributed to iron induced oxidative stress or toxicity of chelation therapy.