Background: The bifurcation angle (BA) is rising as a predictor of outcome after percutaneous coronary intervention for bifurcation lesions. We investigated the impact of BA on clinical outcomes and periprocedural complications in patients with bifurcation lesions from the COBIS registry. Methods: Patients who received percutaneous coronary intervention for bifurcation lesions were enrolled from 16 centers in Korea between January 2004 and June 2006. Patients were divided into 746 patients in the low-angle (��� 49째) and 731 patients in the high-angle group (> 49째) using the median BA as the cut point. We compared major adverse cardiac events (MACE), including cardiac death, myocardial infarction, and target lesion revascularization and periprocedural complications between the two groups. Results: We evaluated 1,477 patients with bifurcation lesions and the median follow-up duration was 22 months. The incidences of MACE were not significantly different between the low-angle and the high-angle group (6.4% vs. 6.7%, P = 0.855). The rate of coronary dissection was higher in the high-angle group (1.7% vs. 3.4%, P = 0.041). The rate of MACE were not significantly different in patients treated with side-branch stenting (9.8% vs. 5.9%, P = 0.328), non-side branch stenting (5.5% vs. 6.8%, P = 0.349), and in patients treated with T-stenting technique (11.6% vs. 8.3%, P = 0.597) between the low-angle and the high angle group. In patients with true bifurcation lesions, there was no significant difference in the incidences of MACE between the two groups (6.5% vs. 7.2%, P =0.677). Multivariate Cox regression analysis showed that the independent predictors for the occurrence of MACE were the implement of final kissing balloon inflation, creatinine >2.0, acute coronary syndrome, and the use of TAXUS for the treatment of parent vessel. Conclusions: In patients with bifurcation lesions, the incidence of coronary dissection during procedure was lower in the low-angle group. However, BA does not influence the clinical outcomes regardless of side-branch stenting, treatment techniques, and the presence of true bifurcation lesions.