Summary Absence of the arterial duct has been reported in association with tetralogy of Fallot, with pulmonary stenosis or atresia, other complex cyanotic congenital heart diseases, and anomalies of the aortic arch but not, as far as we are aware, with tricuspid atresia. We report the clinical, surgical, and autopsy findings of a patient with tricuspid atresia whose initial clinical course was influenced by the absence of thearterial duct.