Objectives: We compared long-term outcome after revascularization for functional versus total occlusions of the non-culprit vessels in patients with acute myocardial infarction (MI). Background: In patients with chronic total occlusion (CTO), the presence of functional occlusion, compared to total occlusion, is associated with successful results of percutaneous coronary intervention (PCI) and may bode well for long-term clinical outcome. Methods: A total of 624 patients enrolled in the e-CTO Club Registry who had acute MI (63짹12 years, male 73%, ST-elevation MI 46%) with a totally occluded non-culprit vessel were divided into 2 groups: group 1 (functional occlusions, n=87) and group 2 (total occlusions: n=537). Two-year clinical outcomes after PCI were compared between the groups. Results: Functional occlusions were more common in females than in males (20.5% vs. 11.5%, P=0.004) and in non-ST-elevation MI than in ST-elevation MI (17.4% vs. 9.8%, P=0.006). There were no differences between group 1 and 2 in treated vessels, lesion lengths, or stent type (drug-eluting stents: 74.7% vs. 65.7%). The 2-year rates of death and major adverse cardiac and cerebrovascular events (MACCE: death, MI, repeat revascularization, and stroke) were similar between the groups: 1.1% vs. 1.5% and 2.3% vs. 3.5%, respectively. Predictors of 2-year MACCE included smoking (odds ratio [OR], 3.27; 95% confidence interval [CI], 1.15~9.27; P=0.026) and non-ST-elevation MI (OR, 3.21; 95% CI, 1.16~8.77, P=0.024). Conclusions: Long-term outcome of PCI was similar between functional and total occlusions of the non-culprit vessels in patients with acute MI.