Background: The clinical and angiographic characteristics identifying high-risk subsets of patients with unprotected left main coronary artery (LMCA) disease undergoing percutaneous coronary intervention (PCI) might be critical for optimal management and improving outcomes. Methods and Results: Between 2000 and 2006, a total of 1102 patients with unprotected LMCA disease received PCI with stenting. During long-term follow-up of median 5.2 years, 138 patients died and 171 patients had target-vessel revascularization (TVR). Twenty-six pre-procedural parameters were evaluated by univariate and multivariate Cox regression analysis to identify independent predictors of all-cause mortality, composite outcome of death, Q-wave myocardial (MI) infarction or stroke, and TVR. Independent predictors of all cause of mortality and composite outcome of death, Q-wave MI or stroke were old age, peripheral vascular disease, renal failure, extent of diseased vessel. Major predictors of TVR were old age, distal LMCA involvement, and right coronary artery disease (Table). Conclusions: Several clinical and angiographic characteristics were identified as important predictors for long-term adverse outcomes after stenting in patients with unprotected LMCA disease. Considering these factors may be helpful to guide optimal treatment strategy for these, ���high-risk��� patients.