Many combinations of anticoagulants and antiplatelet drugs have been used to treat patients undergoing a percutaneous coronary intervention (PCI). Among anticoagulants, enoxaparin has some theoretical advantages over unfractionated heparin, but in clinical trials no advantage in outcome has been demonstrated in PCI. Bivalirudin, a direct thrombin inhibitor, has been associated with a lower risk of bleeding than unfractionated heparin. Among antiplatelet drugs, use of clopidogrel plus aspirin has led to a reduction in cardiovascular events; all patients undergoing PCI should receive both. Addition of a GP IIb/IIIa inhibitor may lower mortality rates further, particularly in high-risk patients such as diabetics.