Objective The optimal antithrombotic regimen for patients on oral anticoagulation (OAC) after acute coronary syndrome (ACS) and percutaneous coronary intervention (PCI) remains debated. This study sought to evaluate the efficacy and safety of OAC plus clopidogrel with or without aspirin in a real-world setting. Methods We retrospectively analyzed data from an international, multi-center registry between 2003 and 2014 (n = 15,401). Patients with ACS and receiving OAC after PCI were screened. The composite primary endpoint was 1-year all-cause death, re-infarction, or severe bleeding. Results The final analysis enrolled 642 patients including 62 patients (9.7%) with OAC and clopidogrel (dual therapy), and 580 patients (90.3%) with the combination of aspirin, OAC and clopidogrel (triple therapy). Patients on triple therapy were more often female and were more likely to have comorbidities. There was no significant difference regarding the primary end point between dual therapy with triple therapy patients [17.74% vs. 17.24%; unadjusted hazard ratio (HR): 1.035; 95% confidence interval (CI): 0.556-1.929; adjusted HR: 1.026; 95% CI: 0.544-1.937]. However, the re-infarction rate was significantly higher in dual therapy than triple therapy patients (14.52% vs. 5.34%; unadjusted HR: 2.807; 95% CI: 1.329-5.928; adjusted HR: 2.333; 95% CI: 1.078-5.047). In addition, there was no difference between two regimes in all-cause death and severe bleeding. Conclusions In real-life patients with ACS following PCI and with an indication of OAC, triple therapy was not associated with an increased rate of adverse outcomes compared to dual therapy. Moreover, it decreased risk of re-infarction and did not increase risk of severe bleeding.