Background and Objectives : The aim of study is to determine clinical outcomes of DES usuage in on or off-label conditions at routine clinical practice Materials and Methods : From April 2005 to August 2006, consecutive patients who were implanted with DES were enrolled in this study. The patients were divided into 2 groups based on the presence of at least one off-label characteristics which were not indicated on the package descriptions of sirolimus- and paclitaxel-eluting stents. The major adverse cardiac events (MACE) were analyzed during the index admission, at one month and one year Results : Of the 517 patients, 262 patients (50.7%) had at least one off-label indications During the hospitalization, no MACE occurred in on-label patient and death due to cardiogenic shock occurred in one patient of off-label patient (0.4%, p=1.0). At one month, MACE occurred only in 3 off-label patients (1.1%, p=0.087). At one year, MACE occurred more high in off-label than on-label patients (1.2% vs 6.2%, p=0.003). Stent thrombosis (ST) occurred only in 4 off-label patients (1.6%); 1 subacute ST, 3 late ST. Conclusion : Although off-label use of DES shows comparable outcomes in short term, long-term clinical outcomes may be more worse than on-label usuage.