Aim : The aim of this study is to compare the clinical outcome of coronary artery bypass graft (CABG) surgery, percutaneous coronary interventions (PCIs) and pharmacological therapy of patients with chronic total occlusion (CTO). Methods : In this single-center and retrospective study, we analized clinical and angiographic data in 236 patients with 278 CTO between January 2007 and October 2009. A CTO was defined as a 100% luminal narrowing with significant decrease in blood flow (TIMI 0-1). We categorized patients as revascularizaion group (Group 1) and pharmacological therapy group (Group 2). Revascularization group were divided to two groups ( Group A : PCI group (n=66) vs Group B : CABG group (n=42). Also, pharmacological therapy group were divided two groups ( Group C : initail medical therpy group (n=55), Group D : revascularizaion failed group (n=73). The study endpoint was the 1-year major adverse cardiac events (MACE). Results: The baseliene clinical characteristics between revascularizaion group and pharmacological therapy group were similar. During follow-up periods (median follow-up : 2.3 years, IQR 1.3-3.3years), MACE developed in 36 patients (15.2%) ( group A : n=6 (9.1%), group B : n=6 (14%), group C : n=17 (30.9%), group D : n=6 (8.2%), p=0.008 ). There were no significant difference on the MACE of group A vs group B (n=6 (9.1%) vs n=6 (14%), p=0.76) and group A vs failed PCI pts of group C (n=6 (9.1%) vs n=5 (9.1%), p=0.86). Patients with left main disease or proximal LAD CTO lesion showed high incidence of MACE (left main : OR 1.2 95% CI, 0.9-1.6 p=0.29, pLAD CTO : OR 1.4 95% CI, 1.1-2.4 p=0.41). And diabetes and severe left ventricular systolic dysfunction had no influence on the outcome of CTO patients. Conclusions: Successful revascularization of CTO improved clinical outcomes of CTO patients. There was no significant difference on the outcome between CABG or PCI patients group.