We evaluated the results of administering recombinant human erythropoietin (rHuEPO) and iron in 19 randomly selected premature infants, who had no infections, did receive oxygen support or aminophylline. rHuEPO was administered intravenously from days to 37 (biweekly) in a dose of 100 U/kg (group I) or 400 U/kg (group II). Also, infants in both groups were supplemented with 10 mg/kg/week of iron intravenously. Seven of 19 infants did not receive either rHuEPO or iron (group III). Infants of all groups had similar birth weights, gestational age and hematocrit, RBC count as well as total and fetal hemoglobin concentrations in blood obtained within the first hour of life. However, infants treated with 400 U/kg of rHuEPO required a significantly (p < 0.04) lower volume of packed erythrocytes in comparison to untreated infants, both between days 7 and 37 of life (18.6 ml vs 46.8 ml; p < 0.04) and between day 7 of life and the day of discharge (35.8 ml vs 94.2 ml; p < 0.04). No difference in neutrophil count, fetal hemoglobin concentration and no toxicity were observed in infants treated with rHuEPO in comparison to untreated prematures.