Data from a prospective study of 50,826 neonates were used to determine the frequency and significance of disorders related to apnea in newborns. Such apnea proved to be a significant prognosticator for neonatal death. Fifty-eight percent of preterm neonates with multiple apneic episodes and 18% with a single episode died, whereas only 6% of those without recorded apnea died. The rates were 44%, 5%, and 1% for full-term infants. Amniotic fluid infection was the underlying disorder in 35% of the preterm and 25% of the term neonates who had multiple episodes of apnea. A third of the preterm and 25% of the term infants who had such apneic episodes had antecedent hypoxia-related disorders, i.e., abruptio placentae, erythromblastosis fetalis, placenta previa, large placental infarcts, and umbilical cord compression. Among the apneic neonates, those who were infected were twice as apt to die as were those who had hypoxia-related disorders. Hypoplasia of the lungs and easily recognized central nervous system malformations were responsible for most of the apnea-related deaths associated with congenital malformations.