The urines of 26 male premature babies, and the blood of 10 of them after milk feedings, were examined by paper chromatography. Most of them excreted less than 100 mg/100 ml of sugar in the urine. The reducing sugars found in 77 of 152 urines examined included glucose, galactose, lactose and xylose or combinations of these on one or more occasions. Galactose and lactose were not found before milk had been fed. A higher proportion of sugars was excreted by the premature babies than in a group of full-term babies. Immaturity of the liver is discussed as a possible cause of the failure of the premature infant to metabolize galactose and lactose fully.