Meconium ileus and pancreatic changes, as described in cystic fibrosis, were found, at autopsy, in a series of six infants who received prolonged neonatal intensive care for prematurity. Cystic fibrosis had not been suspected clinically. These pathological findings are so frequent in sick premature infants, amounting to 12% of all neonatal autopsies conducted over a period of 2 yr in our unit, that we question their specificity for cystic fibrosis and suggest they may be a manifestation of disordered physiology in the severely ill neonate. (Pediatr Res 20: 536-541,1986)