Congenital supravalvar aortic stenosis is an obstruction caused by localized or diffuse narrowing of the aortic lumen commencing immediately above the aortic valve. We experienced a case of diffuse supravalvar aortic stenosis involving ascending aorta from just above the sinuses of Valsalva to the proximal l cm of the innominate artery. Supravalvar aortic stenosis in this patient, in contrast to the form seen in infants and children, was not associated with mental retardation, peculiar faces or the syndrome of hypercalcemia. Diagnosis was confirmed by retrograde left heart catheterization and left ventriculography. Surgical correction was performed by the replacement of oval shaped Woven Dacron patch over the narrow segment of aorta under the cardiopulmonary bypass. Blood pressure was controlled sufficiently with some adjunct of Inderal postoperatively. The patient was discharged with much improvement.