Supravalvular aortic stenosis is a rare congenital anomaly characterized by variable amounts of left ventricular outflow tract obstruction distal to the aortic valve. Macroscopically, it is categorized into three morphologic subtypes: membranous, hourglass, and diffuse. The diffuse type is the most rare, and its surgical repair is the most challenging due to variable length of ascending aorta hypoplasia. Surgical treatment options of supravalvular aortic stenosis are well established for the membranous and hourglass type, whereas they are challenging and less well defined for the diffuse type. We present a case of long-term follow-up (29 years) after a very complex surgical repair of supravalvular aortic stenosis of the diffuse type, with focus on technical aspects. To our knowledge, the present case represents one of the longest follow-up routines in the English language literature of surgical treatment of supravalvular aortic stenosis.