During the last ten years we have considerably update our knowledge about the pathogenesis of unstable angina or acute coronary syndromes. The platelet activity have in this settings the central role in development of the thrombotic process. Platelet glycoprotein IIb/IIIa inhibitors block fibrinogen binding to platelets, and the effect of this on the final common pathway of platelet aggregation makes these compounds extremely potent antiplatelet drugs. Three intravenous IIb/IIIa receptor antagonists are approved for clinical use, and this class of therapy has update our pharmacologic armatarium to avoid ischemic complication in the settings of percutaneous coronary revascularization at first and now in medical treatment of acute coronary syndromes. Results of large trials using this drugs suggest that this agents are effective in patient with unstable angina particularly in those presenting a high score of risk for acute ischemic events and those requiring coronary intervention.