We describe two patients who both presented shortly after birth with congestive heart failure due to an absent pulmonary valve and patent ductus arteriosus. Diagnostic evaluation revealed in both cases an aneurysmatic dilation of the pulmonary vascular tree and an abundant left-to-right shunt over a large patent ductus arteriosus. Ventricular septal defects were not detected. Early surgical closure of the patent ductus arteriosus improved the hemodynamic situation so that implantation of a homograft valve could be delayed.