Iron deficiency anemia is a serious health problem that affects the physical and cognitive development of children. Therefore, it is important to develop cost-effective interventions to improve the hematologic status of the millions of children affected by this condition worldwide. We studied 69 Guatemalan infants who had been randomly assigned to one of three groups at the time of delivery: 1) cord clamping immediately after delivery (n = 21); 2) clamping when the cord stopped pulsating, with the infant placed at the level of the placenta (n = 26); or 3) clamping when the cord stopped pulsating, with the newborn placed below the level of the placenta (n = 22). Maternal and infant hematologic assessments were performed at the time of delivery and 2 mo postpartum. At baseline the groups had similar socioeconomic, demographic, and biomedical characteristics and the newborns had similar hematocrit status. Two months after delivery, infants in the two groups with delayed cord clamping had significantly higher hematocrit values and hemoglobin concentrations than did those in the early-clamping group. The percentage with hematocrit values < 0.33 was 88% in the control group compared with 42% in group 2 and 55% in group 3 (P = 0.01). These results suggest that waiting until the umbilical cord stops pulsating (approximately 1 min after delivery) is a feasible low-cost intervention that can reduce anemia in infants in developing countries.