Quadricuspid aortic valve in adulthood is a rare pathology which often leads to aortic valve regurgitation that requires surgical treatment. Herein are described two patients with severe regurgitation on a quadricuspid aortic valve and with dilated left ventricle, who where successfully repaired using a technique of tricuspidation of the valve at the level of the abnormal commissure. In each patient, the repair was stabilized and leaflet coaptation increased by subcommissural annuloplasty stitches at the level of the three commissures. After one year and six months' follow up, respectively, both patients presented with trivial aortic regurgitation and good mobility of the three leaflets.