The development of new antithrombotic molecules which induced an inhibition of activated factor X (fondaparinux, Arixtra) shows effectiveness and safety in prevention of thromboembolic disease in surgery, but also in the treatment of the pulmonary embolism and major venous thromboses and acute myocardial infarction. Recent clinical trials show that new anti-Xa inhibitors also have interesting properties in antithrombotic therapy. Fondaparinux could offer new therapeutic possibilities that could simplify the management of patients under anticoagulant treatment.