Introduction Erythropoietin is a glycoprotein hormone produced primarily by cells of the peritubular capillary endothelium of the kidney and in hepatocytes in lesser amounts. Erythropoietin is responsible for the proliferation and differantiation of erythroid progenitors and especially erythriod colony forming units [1,2]. Enzyme immunoassays which can readily quantitate serum erythropoietin levels are currently available [3-5]. In order to evaluate the differences in serum erythropoietin (sEpo) levels in different anemia groups among pediatric patients, we worked sEpo levels in iron deficiency anemia, acute lymphoblastic leukemia (ALL), fanconi anemia (FA), thallasemia intermedia (TI) and healthy controls. Recombinant human erythropoietin (rHuEpo) has become an essential part of the management of anemic patients with end-stage renal disease. It is also used to treat the anemia associated with cancer and other diseases, and it improves quality of life [6,7]. In recent years, studies have focused on the use of rHuEpo for other indications. Additionaly, we aimed to define the therapeutic role of rHuEpo in these disease groups, if any deficiency of sEpo was demonstrated.