PURPOSE: We investigated the iron status of very low birth weight infants receiving multiple erythrocyte transfusions during hospitalization in the neonatal intensive care unit (NICU). METHODS: We enrolled 46 very low birth weight infants who were admitted to the Kyungpook National University Hospital between January 2012 and December 2013. Serum ferritin was measured on their first day of life and weekly thereafter. We collected individual data of the frequency and volume of erythrocyte transfusion and the amount of iron intake. RESULTS: A total of 38 (82.6%) of very low birth weight infants received a mean volume of 99.3+/-93.5 mL of erythrocyte transfusions in NICU. The minimum and maximum serum ferritin levels during hospitalization were 146.2+/-114.9 ng/mL and 456.7+/-361.9 ng/mL, respectively. The total volume of erythrocyte transfusion was not correlated to maximum serum ferritin concentrations after controlling for the amount of iron intake (r=0.012, p=0.945). Non-transfused infants took significantly higher iron intake compared to infants receiving > or =100 mL/kg erythrocyte transfusion (p<0.001). Minimum and maximum serum ferritin levels of non-transfused infants were higher than those of infants receiving <100 mL/kg erythrocyte transfusions (p=0.026 and p=0.022, respectively). Infants with morbidity including bronchopulmonary dysplasia or retinopathy of prematurity received a significantly higher volume of erythrocyte transfusions compared to infants without morbidity (p<0.001). CONCLUSION: Very low birth weight infants undergoing multiply erythrocyte transfusions had excessive iron stores and non-transfused infants also might had a risk of iron overload during hospitalization in the NICU.