OBJECTIVE: to assess the effect of delayed clamping of the umbilical cord on hemoglobin concentrations in infants up to three months of age born to anemic and non anemic mothers. METHODS: Mothers and infants born of vaginal delivery, full-term and no abnormalities (325 pairs) were recruited at a hospital in São Paulo, Brazil, in 2006. Maternal hemoglobin concentration at delivery, umbilical cord hemoglobin and ferritin were collected. At approximately three months of age, 210 (64.6%) infants had their hemoglobin concentrations, socioeconomic, anthropometric and infant feeding practices collected. The data were analyzed by multiple linear regression models for anemic mothers (< 11.0 g/dL) (42) and non-anemic mothers (168). The dependent and explanatory variables include ([hemoglobin at three months - umbilical cord hemoglobin / umbilical cord hemoglobin]*100) and immediate/delayed cord clamping, respectively. RESULTS: the infants born to non anemic mothers who received delayed cord clamping have achieved an increase in hemoglobin at three months, around 4%. CONCLUSION: The delayed cord clamping benefits the hemoglobin status of infants, especially those born to non anemic mothers.