Galactose and glucose concentrations were measured in peripheral blood in relation to ad libitum milk feeding in 11 healthy near-term infants. Galactose and glucose concentrations before feeding averaged 1.06 ± 0.21 and 60.3 ± 3.2 mg/dl, respectively. After feedings containing 0.76–2.68 g lactose/kg body weight, both galactose and glucose rose by approximately 35%. Galactose concentrations rose by 0.72 ± 0.10 mg/dl at 30 min after feeding, while glucose concentration rose by 23.3 ± 2.5 mg/dl at 30 min after feeding. The 25-fold greater absolute increase in the concentration of glucose than galactose is consistent with efficient first-pass clearance of galactose by the neonatal liver.