Introduction: Erythropoietin (Epo) is a hormone that is synthesized in the kidneys and that stimulates the erythropoiesis in the bone marrow. Epo has effects apart from the erythropoiesis. In chronic renal failure (CRF) patients, hemorrhagic diathesis is observed, and Epo production is decreased. Erythropoiesis-stimulating agents (ESAs) are widely used in the treatment of renal anemia in these patients. Our study aimed to investigate the effect of ESA5 use on platelet aggregation in peritoneal dialysis (PD) patients due to CRF.