Vaso-occlusive disorders because of arterial thrombosis which include unstable angina, myocardial infarction (MI), transient ischemic attacks (TIAs), stroke and peripheral vascular disease remain major sources of morbidity and mortality throughout the world. Platelet activation and aggregation play a major role in the pathogenesis of these thromboembolic diseases. Recognition of the contribution of platelets to the pathophysiology of cardiovascular disease (CVD) has provided impetus for the continued search for new antiplatelet agents. There are two classes of antithrombotic agents, that is, antiplatelets and anticoagulants. Antiplatelet agents are explained. Anticoagulants are described. Thrombolytic agents are discussed.