Classic anticoagulant drugs are very effective, save lives and have been used for more than 50 years. Nevertheless, some drawbacks are encountered in their routine clinical use. Recently, pharmaceutical research has developed new drugs, some of which are already on the market. This is the case of fondaparinux, a pentasaccharide which can interact with antithrombin, thus inhibiting factor Xa. Modification of its structure (idraparinux) has led to more stable binding with antithrombin and to an increase in its half-life allowing for once-a-week administration. Another important oral compound is ximelagatran which directly binds thrombin and blocks its catalytic site. There is no need for laboratory control, and phase II and phase III studies are encouraging. Thus, in the next few years, we may witness great changes in the treatment of patients with thromboembolic disorders.