Asphyxiating thoracic dystrophy is an autosomal recessive disorder characterised by an abnormally small thorax, variable shortening of the extremities, and pelvic anomalies. Renal and pancreatic symptoms are found in longer survivors, although most cases die in infancy of respiratory failure. Seven neonatal cases were studied at necropsy. These cases ranged in gestational age from 32 to 40 weeks. One was stillborn and the other six survived from 1 hour to 10 days. Two were sibs born to consanguineous parents. Dwarfing was not pronounced and the extremities were shortened in only one infant who also had polydactyly. All seven showed visceral changes in addition to abnormalities of bone. Endochondral ossification was irregular in sections of femur, vertebra, and rib. Pulmonary hypoplasia was associated with the small thorax typical of this disorder. Periportal fibrosis and bile duct proliferation were seen in sections of liver, and in one case cirrhosis was found. Pancreatic fibrosis was variable. These necropsy findings correlate with later clinical manifestations of the disease and emphasise the multisystem nature of this disorder.