The study proposed to assess glomerular filtration rate as determined by endogenous creatinine clearance in steady state Nigeria children with homozygous sickle cell disease and normal controls. Twenty-four hours urinary creatinine clearance was estimated over a 6-month period in 54 steady-state homozygous sickle cell disease and 57 normal control children aged 5 to 13 years. Each child was admitted and a 24-hour urine sample (8.00 am to 8.00 am) was collected both for volume measurement and creatinine concentration determination. Blood was also collected from each child 30 minutes to end of urine collection for plasma creatinine concentration determination, haematocrit and reticulocyte counts. The results were compared between the two groups of children using student's t-test and the chi (X2) square test where necessary. The mean glomerular filtration rates +/- SD (ml/min/1.73 M2) for homozygous sickle cell disease children and normal controls were not significantly different (p > 0.05). Glomerular filtration rate did not differ significantly between the age groups in both patients and normal controls; haematocrits correlated weakly with glomerular filtration rates in the patients (r = +0.213; p < 0.001). Nigerian children with homozygous sickle cell disease who are in steady states have normal glomerular filtration rate that is hardly influenced by increasing age and low haematocrit level.