The nitrogen economy of sickle cell patients has been found to be FRpaired due to several factors including poor absorption of protein products and higher than normal urinary nitrogen excretion. The increased urinary loss of nitrogen is probably due to increased protein catabolism as a result of inadequate intestinal supply of nitrogen and its poor utilization. The relationship between urinary nitrogen excretion and dietary nitrogen intake was investigated. The results confirmed that there was higher than normal nitrogen excretion in the sicklers at all levels of nitrogen intake. Creatinine excretion, expectedly, was lower in the sicklers due to their smaller physical stature. Uric acid excretion was higher in the sicklers, and so was the mean urine acid to creatinine ratio (0.64 in the sicklers and 0.34 in the normals). The ratio was not affected by the diet, indicating that there was increased purine metabolism in the sicklers.