Cardiac valve replacement is associated with a thromboembolic risk, particularly during the immediate postoperative period. The current anticoagulation recommendations for biological valves are variable and their application by the surgical centers is unconstant. Some centers continue to anticoagulate all patients who receive a heart valve replacement for 3 months, without distinction of valve position (mitral or aortic) at the cost of bleeding complications. However, more recent studies suggest that anticoagulation may not be necessary for biological valves in aortic position in the absence of associated embolic risk factors. Prospective and randomized studies are still needed to establish more definitive evidence regarding the prevention of thromboembolism for bioprostheses.