The aim of this study was to evaluate the impact of prolonged dual antiplatelet therapy (DAPT) on clinical outcomes in patients undergoing percutaneous coronary interventions (PCI) for bifurcation coronary lesions. A total of 1000 patients who underwent PCI for coronary bifurcation lesions and had clinical follow-up were divided into two groups based on the duration of DAPT: DAPT >12 months and DAPT ≤12 months). Patients who experienced a myocardial infarction, required repeat PCI, or died within 1 year after the initial procedure were excluded. Among the 1000 eligible patients, 394 patients received DAPT for > 12 months (39.4%). Most patients in our study presented with chronic coronary disease (61%). The majority of patients in our study (62.8%) had a low bleeding risk.The median follow-up duration was 35 months (interquartile range 20.6-36.5). There were no significant differences in the major adverse cardiovascular events (MACE) between groups of prolonged DAPT (>12 month) and DAPT ≤12 months (18.8% vs. 14.9%, p = 0.11). Patients with clinical features of high ischemic risk (HIR) had a significantly increased risk of MACE (hazard ratio [HR] 1.92, 95% confidence interval [CI] 1.12-3.26, p = 0.015) when compared with patients without clinical features of HIR. Compared with DAPT ≤12 months, extended DAPT (>12 months) did not improve outcomes in patients with clinical (HR 1.24, 95% CI 0.90-1.72, p = 0.19) and technical features (HR 1.04, 95% CI 0.67-1.63, p = 0.85) of HIR. In this multicenter real-world registry, administration of DAPT for more than 12 months in patients who have undergone PCI for bifurcation lesion is not associated with a reduced incidence of MACE in long-term follow-up. ClinicalTrials.gov identifier no. NCT03450577.