The brainstem development of infants born between 33 and 38 weeks' gestation is less mature than that of a full-term infant. During late gestation, there are dramatic and nonlinear developmental changes in the brainstem. This translates into immaturity of upper airway and lung volume control, laryngeal reflexes, chemical control of breathing, and sleep mechanisms. Ten percent of late preterm infants have significant apnea of prematurity and they frequently have delays in establishing coordination of feeding and breathing. Unfortunately, there is a paucity of clinical, physiologic, neuroanatomic, and neurochemical data in this specific group of infants. Research focused on this group of infants will not only further our understanding of brainstem maturation during this high risk period, but will help develop focused plans for their management.