Background The purpose of this study is to compare the clinical outcomes of patients with coronary chronic total occlusion (CTO) receiving long segment drug-eluting stent (DES) with those implanted short DES. Materials and Methods A total 2127 patients who was diagnosed as CTO and successfully implanted DES were retrospectively enrolled from e-CTO club registry. Group 1 (n=1215) was defined as patients receiving short DES segment less than 40 mm and Group 2 (n=912) as those implanted long DES segment over 40 mm. Major adverse cardiac events (MACE) such as cardiac death, myocardial infarction (MI), target lesion revascularization (TLR) and target vessel revascularization (TVR) and stent thrombosis (ST) were evaluated at 1 year. Results Baseline characteristics between two groups were not different. Stent length was 27.4짹6.4 for Group 1 and 64.8짹18.2 mm for Group 2. Cumulative total MACE rate was significantly higher in long stent group (3.3% in Group 1 vs. 7.3% in Group 2, p<0.001). Although cardiac death (0.6% in Group 1 vs. 1.2% in Group 2, p=0.116) and MI (0.5% in Group 1 vs. 0.4% in Group 2) were not different between two groups, the rate of TLR (1.5% in Group 1 vs. 4.1% in Group 2, p<0.001) and TVR (2.5% in Group 1 vs. 5.9% in Group 2, p<0.001) were higher in Group 1. There were no statistical differences in ST (0.2% in Group 1 vs. 0.1% in Group 1). Conclusion Short segment DES for patients with coronary chronic total occlusion has better clinical outcomes compared with long DES. Key Words: Chronic total occlusion, Drug-eluting stent, long versus short