The increased survival of very-low-birth-weight infants has resulted in the need to better understand the immaturities that challenge optimal nutrition for these infants and how to surmount them. This is critical if we are to prevent short and long term morbidity associated with poor nutrition. Here we describe several of these immaturities including those related to digestion and absorption, suck-swallow incoordination, delayed gastric emptying, and intestinal motility and how they lead to the common problem of feeding intolerance. Scientifically based strategies for introducing, stopping and continuing enteral feedings in association with parenteral nutrition are presented.