There is no perfect prosthetic valve substitute for young and middle-aged patients requiring aortic valve replacement (AVR). The long-term risks of anticoagulation with a mechanical prosthesis must be weighed against the risks of structural valve deterioration of a bioprosthetic valve. In patients aged 20 to 40 years, the decision almost always leads to the selection of a mechanical valve and lifelong anticoagulation. Unfortunately, aortic valve repair is an option for only a small number of patients who are highly selected.