Antiplatelet therapy is a cornerstone in the medical management of acute coronary syndromes. Three classes of antiplatelet drugs are available in this setting: acetylsalicylic acid, thienopyridines, and glycoprotein IIb/IIIa antagonists. During the last ten years, numerous clinical trials have been conducted in large populations of patients suffering from acute coronary syndromes. Further investigations are in progress. In the light of these results, the respective roles of the different antiplatelet drugs have been more precisely defined, in terms of class preference as well as in terms of the combination of several antiplatelet drugs and of antiplatelet drugs with other therapies, including non fractionated--or low molecular weight--heparin and non-invasive or invasive revascularisation procedures. In the present article, we review the results of the major published or non published trials that addressed the role of glycoprotein IIb/IIIa antagonists in the management of acute coronary syndromes. Based on these results, the current therapeutic guidelines for clinical practice issued by the American and European cardiology societies are given in the conclusion, with their level of evidence.