The influence of coffee consumption on hematological and trace element status was studied in two groups of pregnant, low-income Costa Rican women: coffee drinkers (greater than or equal to 450 mL/d, n = 22) and coffee nondrinkers (0 mL/d, n = 26). Groups had similar income, education, prenatal care, age, parity, weight, height, pregnancy weight gain, prenatal iron supplementation, energy, protein, Fe, and vitamin C intake and infant sex and gestational age. Maternal hemoglobin (Hb) and hematocrit (Hct) at 8 mo gestation, cord blood Hb and Hct, infant birth weight and Hb and Hct at 1 mo of age, and breast-milk Fe concentration were significantly lower in the coffee group than in the noncoffee group. The association of coffee with infant Hb and Hct was independent of maternal Fe status and birth weight. These results are consistent with our previously reported data in rats and indicate that maternal coffee intake may contribute to maternal and infant anemia.