Secondary hyperparathyroidism and anemia are the hallmarks in uremic patients. It is suggested that parathyroid hormone increases erythrocyte osmotic fragility and induces hemolysis. The present study was undertaken to examine the possible relationship between erythrocyte osmotic fragility and secondary hyperparathyroidism in 20 pediatric patients on maintenance peritoneal dialysis. We found that erythrocyte osmotic fragility in these patients was normal. No correlation between erythrocyte osmotic fragility and hematochemical changes associated with secondary hyperparathyroidism was found. We conclude that erythrocyte osmotic fragility was normal in pediatric patients on peritoneal dialysis and excess parathyroid hormone levels do not affect erythrocyte osmotic fragility and do not cause anemia.