Three patients with far-advanced cystic medial necrosis of the aorta, which had produced giant bulbous enlargement of the aortic root and severe aortic regurgitation, were operated on using a procedure not previously described. Measurements of the aortic valve annulus and ascending aorta were made from aortograms. A knitted polyester arterial prosthesis was sewn together to form a circle. This circular prosthesis was sewn to a 31 mm Björk-Shiley aortic valve prosthesis in the way that a tire is fitted onto a wheel. The resulting composite prosthesis, which had the same diameter as the aortic root, was used to replace the excised valve. In all cases a composite prosthesis measuring greater than 50 mm in diameter was used. In 2 of the 3 patients the ascending aorta was replaced with a tubular graft reshaped as a truncated cone. This reshaping was done by inserting multiple gussets into one end of the aortic prosthesis so that the flanged end fit precisely to the enlarged valve prosthesis and the other end fit precisely to the transverse aortic arch. Two patients are asymptomatic more than two years following operation. The third patient died suddenly of a ventricular arrhythmia on the twenty-third postoperative day.