Congenital absence of the pulmonary valve leaflets Is generally associated with ventricular septal defect, anular pulmonary stenosis and aneurysmal dilatation of the pulmonary arteries: the absent pulmonary valve syndrome. Symptomatic infants with this syndrome suffer primarily from respiratory insufficiency caused by bronchial compression by the dilated pulmonary arteries, and have a high mortality rate. Asymptomatic Infants are thought to do well, and may have elective surgery late in childhood. Findings In four infants with absent pulmonary valve syndrome are reviewed. One symptomatic Infant was successfully treated with closure of a ventricular septal defect and pulmonary arterial plication. One previously asymptomatic Infant had a fatal respiratory arrest revealing the complexity of management of infants with absent pulmonary valve syndrome.