Background: Patients with sickle cell anemia have various forms of renal dysfunction. Subjects, materials and methods: The purpose of this study is to demonstrate the abnormalities of HbSS patients' renal function in childhood. Renal function studies were performed in 55 patients with homozygote sickle cell anemia and compared with 13 healthy children. The blood and timed urine samples were obtained for hematological and biochemical determinations. Results: Mean serum creatinine, sodium, phosphorus and calcium levels were not statistically different between patients and controls. Mean serum potassium and uric acid levels were significantly higher in patients than in controls. Mean tubular phosphate reabsorption (p<0.001) and fractional excretion of potassium (p<0.05) were lower in patients than in the control. There were no significant differences in fractional excretion of sodium and uric acid between patients and controls. Patients had significantly higher urine pH and significantly lower specific gravity and osmolality than controls. Also, there were no significant differences in urinary protein/creatinine, urinary N- acetyl- -D- glucosaminidase/creatinine and urinary malondialdehyde/creatinine between patients and controls. Conclusion: Thus, significant proximal tubular dysfunction is not a common feature but distal tubular abnormality is the most consistent renal functional derangement of patients with SCA in childhood.