Diagnostic features of the absent pulmonary valve syndrome are reported. Association of this syndrome with ventricular septal defect, tetralogy of Fallot and tricuspid atresia is stressed. Severe ventilatory problems are frequent during the neonatal period. A exaggerated right ventricular hypertrophy, in comparison with that expected in the usual case of tetralogy of Fallot, is a useful parison with that expected in the usual case of tetralogy of Fallot, is a useful electrocardiographic sign. Complete diagnosis sometimes requires the technique of occlusion aortography sign. Complete diagnosis sometimes requires the technique of occlusion aortography or contrast injections into pulmonary veins.