Understanding of the pivotal role of the platelet surface membrane glycoprotein (GP) IIb/IIIa receptor in platelet aggregation at the injured coronary plaque in acute coronary syndromes has led to recent pharmacologic strategies that focus on inhibition of this final common pathway. Several intravenous medications directed specifically at this receptor (called platelet GP IIb/IIIa receptor antagonists; GPAs) have emerged. These include the human-murine chimeric monoclonal antibody Fab fragment abciximab, the peptide antagonist eptifibatide and the peptidomimetics tirofiban and lamifiban. To date, over 33,000 patients have been studied with these compounds in 11 large, randomized placebo controlled trials which have established the effectiveness of these drugs in conditions where platelet aggregation and thrombosis play major contributing roles such as in high-risk coronary intervention, myocardial infarction and unstable angina. GPAs have been proven to be effective in reducing ischemic complications when used as an adjunct to percutaneous coronary revascularization or the management of acute ischemic syndromes. They are well tolerated and safe, provided concomitant use with other antithrombotics (e.g. heparin) is carefully managed and platelet counts are monitored.