Respiratory failure in newborns with abdominal wall defects has been attributed to increased intra-abdominal pressure and elevation of the diaphragm after closure. Despite surgical techniques designed to minimize intra-abdominal pressure, we have observed prolonged respiratory insufficiency in several such infants. We reviewed the charts of 108 infants from 1975 to 1982 who had abdominal wall defects: 53 with gastroschisis, 29 with small omphaloceles, 22 with liver-containing or giant omphaloceles (GO), and four with cloacal exstrophy. Nine infants with GO (41%) had prolonged respiratory insufficiency and five died. Infants with GO required longer periods of oxygenation and ventilation (P less than .001, ANOVA) than infants with other abdominal wall defects. Clinical observation suggested that infants with GO have a small, narrow thorax. We obtained detailed measurements from the chest radiographs of infants in all groups. After correction for birth weight, babies with GO had smaller chest widths (P less than .001) and lung areas (P less than .05) than infants with other abdominal wall defects. At autopsy, one newborn with GO was found to have severe pulmonary hypoplasia. Prolonged respiratory insufficiency in infants with GO may be explained by pulmonary hypoplasia and/or by a narrow chest deformity which limits lung expansion.