Improved obstetrical and neonatal care has increased survival for many small premature infants. However, there remains a distinct group who die of complications later in infancy. The autopsy findings associated with these "postponed neonatal deaths" were the subject of our retrospective study of 18 premature infants (mean estimated gestational age, 28.6 +/- 0.6 weeks) who survived from 4 weeks to 4 months of age (mean, 70 +/- 11 days). All 18 infants required prolonged artificial ventilatory support and parenteral nutrition. The major findings at autopsy were similar in all cases and included bronchopulmonary dysplasia, hepatic cholestasis and fibrosis, abnormalities of endochondral ossification, and diffuse cerebral gliosis and infarction. Infection was the most common cause of death, and most of the infants died with acute bronchopneumonia. These postponed neonatal deaths, while they do not appear in standard neonatal mortality statistics, represent a problem of concern.