Objective: We aimed to elucidate the structural basis of supravalvular aortic stenosis in the context of its surgical repair, Methods: We examined retrospectively the angiograms and echocardiograms of 37 patients and compared them with those of control groups, Additionally, we studied 8 pathologic specimens. Results: Partial adhesion of the leaflets to the stenosing ridge was observed in 54% of the cases and the leaflets were: thickened and less mobile in 30%, Forty-five percent of the angiograms showed evidence of coronary orificial stenosis. The sinuses of Valsalva were significantly enlarged in 75% of the cases. Changes in dimensions of the aortic root were demonstrated more clearly by angiography than by echocardiography. In all anatomic specimens, a marked redundancy of the leaflets was observed and quantified, Conclusions: Our data demonstrate that the entire valvular apparatus is always affected by the so-called supravalvular stenosis. Anatomic restoration of the aortic root should ideally rake into account all of the deformed components by enlarging all three sinuses of Valsalva at the sinotubular junction.