Background: Drug-eluting Stent (DES) is associated with favorable outcomes for major adverse cardiac events (MACE) as compared with BMS in unprotected left main trunk disease (ULMTD). The aim of this study is to compare the long-term outcome between 1st generation and 2nd generation DES with ULMTD patients who underwent percutaneous coronary intervention (PCI). Methods: From February 2004 and July 2010, 116 patients underwent PCI with 1st DES or 2nd DES for ULMTD patients. 1st DES was receiving in 69 patients and 2nd DES in 47 patients. Major adverse cardiac events (MACE: a composite of cardiac mortality, myocardial infarction (MI), target vessel/target lesion revascularization (TVR/TLR) and stent thrombosis (ST)) was evaluated at 1 years after the index procedure Results: There was no difference in risk factor, DM(27.5% 1st DES vs. 27.7% 2nd DES, p=1.000), HTN(43.5% vs 46.8%, p=0.849), hyperlipidemia(11.6 vs. 14.9%, p=0.779). But there was difference in smoking(42.0% vs 63.8%, p=0.024). There was a higher tendency of MACE in 1st DES (18.8% vs. 6.4% in 2nd DES, p=0.056) without functional significance: cardiac death (8.7% vs. 2.1%, p=0.238), MI (5.8% vs. <0.01%, p=0.146), TLR (4.3% vs. 1.7%, p=0.699), TVR (7.2% vs. 6.4%, p=1.00). The rate of stent thrombosis (ST) was also similar between the two groups (1.4% vs. <0.01%, p=1.000). Conclusions: There was no significant difference in 1-year clinical outcome after PCI in ULMTD between 1st generation DES and 2nd generation DES.