Iron deficiency anemia is a common problem in newborn infants. The American Academy of Pediatrics recommends iron prophylaxis at 4 months of age for term infants. There is no specific recommendation for iron prophylaxis in late-preterm infants. We aimed to establish the optimum time for iron prophylaxis in late-preterm infants. Thirty-eight late-preterm (Group 1) and 38 term (Group 2) infants born on the same day were enrolled in the study. Hemoglobin, ferritin and reticulocyte values at birth, 2nd month and 4th month were assessed. The cord ferritin, hemoglobin and reticulocyte levels did not differ significantly between groups. However, at the 2nd month, median ferritin and hemoglobin values were lower in late-preterm infants than term infants (145 mg/dl vs. 195 mg/dl, p=0.001 and 10.1 g/dl vs. 11.6 g/dl, p<0.001, respectively). Median ferritin levels were lower at the 4th month in latepreterm infants than term infants, but this difference was not significant after exclusion of three late- preterm infants who required iron therapy (49 mg/dl vs. 62 mg/dl, p=0.2). There was a tendency of higher frequency of anemia in late-preterm infants at 4 months (42.8% vs. 21.1%), but this was statistically insignificant (p=0.07). At the 2nd month of age, the median ferritin and hemoglobin levels of late-preterm infants were lower than those of term infants. Further studies with larger sample sizes are required to determine the need for earlier supplementation of iron in late-preterm infants.