Quadricuspid aortic valve is rare and occasionally associated with aortic regurgitation and ascending aortic dilatation. Recent studies suggest an association of aortic regurgitation with ascending aortic medial degeneration.  Histologic evaluation of ascending aortic tissue of two individuals with regurgitant quadricuspid aortic valve, one dilated, one non-dilated, yielded comparable degeneration in the Media.  Regurgitation of quadricuspid aortic valve may lead to the degeneration of Tunica media of the ascending aorta.