Background: There are limited data whether the prognosis of acute non-ST segment elevation myocardial infarction (NSTEMI) patients (pts) with total occlusion in infarct-related artery (IRA) can be worse compared with those of pts with non-total occlusion in IRA in the drug eluting stent (DES) era. Methods: The study population consisted of 2,858 consecutive acute NSTEMI pts enrolled in the Korea Acute Myocardial Infarction Registry (KAMIR) study from November 2005 to June 2008. We compared the clinical outcomes of NSTEMI pts with total occlusion in IRA (TIMI 0.1, n=1159, 40.6%) to those of pts with non- total occlusion in IRA (TIMI 2,3, n=1699, 59.4%) who underwent percutaneous coronary intervention (PCI) with DES. Results: The baseline clinical and procedural characteristics were balanced between pts with total occlusion and non-total occlusion of the IRA except more complex angiographic lesions (80.2% vs. 72.5%, p=0.001) noted in the total occlusion group. More unfractionated heparin (63.8% vs. 58.5%, p=0.004), beta blockers (75.6% vs. 68.7%, p =0.001) and more invasive strategy (51% vs. 28.5%, p<0.0001) were used in pts with non-total occlusion group. At 12 month, major clinical outcomes including mortality, repeat revascularization, any re-AMI, and total major adverse cardiac events (MACE) were similar between the two groups except recurrent NSTEMI were significantly higher in pts with total occlusion group after the multivariate analysis (Table). Conclusion: The prevalence of total occlusion of IRA was significant proportion (40%) in the acute NSTEMI setting and showed similar one year major clinical outcomes regardless of IRA patency at the time of NSTEMI presentation except more cumulative recurrent NSTEMI in the total occlusion group at one year.