The role of platelets is well known in the atherogenesis, acute coronary syndrome and development of complications of percutaneous coronary intervention. Until recently, aspirin was the only antiplatelet agent available for the primary and secondary prevention of coronary heart disease. Over the past several years, there has been a substantial expansion in our antiplatelet armamentarium, as well as in our understanding of the clinical importance of antiplatelet therapy in patients with coronary artery disease. The benefits and limitations of the currently available antiplatelet agents, including aspirin, thienopyridines (ticlopidine and clopidogrel) and the platelet glycoprotein IIb/IIIa blockers, in the secondary prevention of coronary heart disease, and high-risk clinical situations, such as unstable angina, acute myocardial infarction and percutaneous coronary intervention, have been reported. Antiplatelet agents should be used, in proper combination, in all relevant cases, as they have been shown to improve the prognosis of various forms of high-risk patients with coronary artery disease.