Backgrounds : The prevalence of coronary chronic total occlusion (CTO) was about 20-30 % of percutaneous coronary intervention (PCI). It has been established that CTO was a risk factor of adverse clinical outcomes in bare metal stent era. However, there were a paucity of data about the long term prognosis after PCI by drug eluting stent (DES). So we evaluated whether the CTO is poor prognostic factor in DES era. Methods : We enrolled consecutive 433 patients with CTO and 8694 patients without CTO after successful PCI by DES in COACT (CathOlic medical center percutAneous Coronary inTervention) registry from January 2004 to December 2009. The primary end point was a composite of major adverse cardiac events (MACE) including all-cause of death, myocardial infarction, or target vessel revascularization. To investigate whether CTO is poor prognostic factor, we used Cox hazard proportional regression model. Results : Most of the clinical baseline characteristics were similar between two groups. However, in angiographic characteristics, there were more B2/C lesions and more involved vessels in CTO group. And the mean stent diameter was smaller and total stent length was longer in CTO group. After a median follow up of 754 days (interquartile range, 374-1,267 days), there were no significant differences in MACE ( 21.0% vs 19.9%, log-rank p=0.644) between two groups. In Cox hazard proportional regression model, CTO could not predict MACE (Hazard ratio 1.07, 95% confidence interval 0.81-1.40) (Table 1). Conclusion : Long-term clinical outcomes were similar in the CTO and non-CTO revascularized by DES, and the CTO is not the poor prognostic factor in the DES era. Key words : chronic total occulsion, drug eluting stent, major adverse cardiac events