Since a successful balloon angioplasty of coronary artery stenosis in a patient in 1977, the development of percutaneous coronary intervention was remarkable. The drug-eluting stent reduces the occurrence of in-stent restenosis and the need for subsequent target vessel revascularization, when compared with the bare-metal stent. However, the safety of the drug-eluting stent has been called into question because of an apparent increase in late stent thrombosis. With adequate antiplatelet therapy and other optimal medical treatment, the net clinical benefit of the drug-eluting stent may outweigh their risks. The use of drug-eluting stent in the real world is in some cases beyond the indications evaluated in the randomized trials. In a high-risk or complex subset of lesions such as chronic total occlusion, bifurcations, small vessels, long lesions, and saphenous vein grafts, the data appear to be convincing enough to support extended applications. However, in other clinical subsets such as diabetes, multivessel disease, unprotected left main disease, and acute myocardial infarction, more data and longer clinical follow-ups are necessary before implantation of a drug-eluting stent.