A 42-year-old man underwent assumed total surgical repair of an acyanotic tetralogy of Fallot: a perimembranous ventricular septal defect (VSD) was closed with a dacron patch and myectomy of the infundibulum of the right ventricular outflow tract was performed. Reexamination eight years later revealed a large recurrent VSD and by surprise a narrow supravalvular ridge above rudimentary pulmonary cusps in the pulmonary trunk, leading to a pressure drop of 70 mmHg across the supravalvular stenosis. The latter finding was not recognized during the operation eight years before. The diagnosis could noninvasively be established by means of magnetic resonance imaging. During revision surgery the VSD was closed and an aortic homograft was inserted as conduit between the right ventricle and the pulmonary artery.