Coronary artery stent thrombosis (ST), defined as the thrombotic occlusion of a stented segment, is an infrequent but serious complication of percutaneous coronary intervention (PCI). The clinical consequences of ST are severe, because acute stent occlusion results in myocardial infarction and death in up to 45% of cases. Specific patient and procedural characteristics increase the risk of ST, but optimized interventional techniques and antiplatelet therapies have the potential to decrease ST and improve cardiovascular outcomes following PCI.