Background: Although intravascular ultrasound (IVUS) has been widely used for complex lesions during coronary intervention, IVUS for stenting at bifurcation lesions has not been sufficiently assessed. The aim of this study was to investigate the impact of IVUS guidance on long-term clinical outcomes during drug-eluting stent (DES) implantation for bifurcation lesions. Methods: The Korean multicenter bifurcation registry listed 1,668 patients with non-left main de novo bifurcation lesions who underwent DES implantation between January 2004 and June 2006. Using propensity score matching with clinical and angiographic characteristics, 487 patients with IVUS-guidance and 487 patients with angiography guidance were selected. The 3-year clinical outcomes were compared between the two groups. Results Baseline clinical and angiographic characteristics were well matched and showed no significant differences between the two groups. Two stents technique and final kissing ballooning angioplasty were more frequently performed in the IVUS-guided group. Maximal stent diameters at both the main vessel and the side branch were larger in the IVUS-guided group. Periprocedural CK-MB elevation (>3 times of upper normal limits) was frequently observed in the angiography-guided group. The 3-year incidence of death or myocardial infarction was significantly lower in the IVUS-guided group compared to the angiography-guided group (3.8 % vs. 7.8 %, log rank test p = 0.03, Hazard ratio 0.44; 95 CI, 0.12 to 0.96, Cox-model p = 0.04). Conclusions: IVUS-guidance during DES implantation at bifurcation lesions may improve the clinical outcomes by reducing the occurrence of death or myocardial infarction