Seventy premature infants (birthweight 1.75 kg or less, gestational age 33 weeks or less) with hemoglobin less than 10 g/dL and hematocrit less than 30% were studied and randomly divided into three groups. All of them received oral elemental iron 3 mg/kg/day and vitamin E 5 mg/kg/day during the study period. Recombinant human erythropoietin (rHuEPO) 150 U/kg was administered intravenously twice a week for 4 weeks in group A (26 infants). Infants in group A received a total of 4 erythrocyte transfusions because of frequent apnea. Infants in group B (25 infants) received erythrocyte transfusion when their hemoglobin levels was less than 10 g/dL with signs and symptoms (including tachycardia, tachypnea, poor feeding, apnea, poor weight gain) attributed to anemia or who had a hemoglobin less than 8 g/dL even if asymptomatic. Infants in group B received a total of 36 erythrocyte transfusions. Infants in group C (19 infants) were assigned to a non-rHuEPO and nontransfusion group. Three of the 19 premature infants in group C received erythrocyte transfusions later because of frequent and prolonged apneic episodes and were excluded from this study. Our data revealed that reticulocyte and serum erythropoietin values were higher (p < 0.01) in rHuEPO-treated group than transfusion group and hemoglobin and hematocrit values were lower in group C than the other two groups during the rHuEPO treatment period. No significant difference (p > 0.05) was found in neutrophil and platelet counts among these three groups. Serum ferritin values were found lower in the rHuEPO-treated group than the other two groups. Lower weight gain was found in infants in group C. We conclude that rHuEPO administration can reduce the need for blood transfusion. Poor weight gain can be found in infants with anemia of prematurity who do not receive rHuEPO or blood transfusion therapy.