Thirty full-term infants born with surgically correctable life-threatening abnormalities who underwent emergency neonatal surgery were followed up from birth to 3 years of age. Comparable data were obtained on a matched group of healthy newborn babies. At 3 years the cognitive functioning of children whose condition had been resolved in the early months of life was similar to the controls. Those children who required further medical or surgical treatment were functioning at lower levels than the controls, with language development being most affected. Number of operations, defined as all procedures under general anesthetic, was the medical factor most strongly associated with poorer outcome at 3 years. Family factors--higher maternal IQ and nonmanual social class--were also positively correlated with language development.