The directors of 269 neonatal intensive care units were surveyed to determine how low-birth-weight infants are being fed. Feeding practices were based on birth weight, with the smallest infants receiving parenteral nutrition for the longest time after birth. First enteral feedings usually were given by the nasogastric route in infants with birth weight of 1,500 g or less, but transpyloric feedings were used in 15% of neonatal intensive care units for infants with birth weight less than 1,000 g. The initial enteral feeding was sterile water in 56% to 58% of the neonatal intensive care units, but was glucose water or milk in the others. Once enteral feeding was established, both human milk from the infant's own mother and commercial formula were used. Whether human milk was mixed or alternated with infant formula, or whether some infants in the nursery were fed human milk while others were fed formula, was not determined. The type of infant formula fed to low-birth-weight infants depended on the infant's birth weight and clinical status. Both human milk and formula were supplemented with energy (fat or carbohydrates) and vitamins, but not with calcium and phosphorus, in most neonatal intensive care units. Some vitamins, such as vitamins A and D, may be oversupplemented, while others, such as folic acid, may be undersupplemented.