Knowledge of gastrointestinal ontogeny provides a rational basis for the use of enteral nutrition in the preterm infant. In all but the least mature infants, digestive and absorptive capacity is good. Immature motility commonly results in gastrointestinal problems, which include poor toleration of milk feeds, gastro-oesophageal reflux, and inadequate gastric emptying. Problems are exacerbated by poor fetal health and intra-uterine growth retardation. These considerations are important in the choice of method of nutrition. When parental nutrition is used, minimal enteral feeding has beneficial effects upon maturation of gut motility.