Background: We previously reported that dual antiplatelet therapy (DAPT) with cilostazol was superior to aspirin or clopidogrel for the prevention of recurrent stroke and vascular events in a subgroup analysis of intracranial arterial stenosis in the Cilostazol Stroke Prevention Study for Antiplatelet Combination ( CSPS.com ), a randomized controlled trial. Aims: We conducted another subgroup analysis to investigate the benefit of DAPT with cilostazol in patients with extracranial arterial stenosis (ECAS) and those without arterial stenosis. Methods: We compared the risk of recurrent ischemic stroke, vascular events, and major bleeding between DAPT with cilostazol plus aspirin or clopidogrel and aspirin or clopidogrel alone in patients with ischemic stroke between 8 and 180 days before starting trial treatment and ECAS or without arterial stenosis. Results: The median follow-up period was 1.4 years. The risk of recurrent ischemic stroke (hazard ratio (HR): 1.04, 95% confidence interval (CI): 0.42–2.57) and vascular events (HR: 0.97, 95% CI: 0.42–2.24) did not differ between the two groups for the 253 patients with ECAS, whereas they were lower (HR: 0.36, 95% CI: 0.18–0.74 and HR: 0.47, 95% CI: 0.26–0.85, respectively) in the DAPT group for the 944 patients without arterial stenosis. The risk of major bleeding did not differ between the groups in patients with ECAS (HR: 0.58, 95% CI: 0.05–6.39) or without arterial stenosis (HR: 0.79, 95% CI: 0.27–2.26). Conclusion: DAPT with cilostazol might be beneficial for prevention of recurrent stroke and vascular events in patients without arterial stenosis but not in those with ECAS. Data access statement: We will make the deidentified participant data from this research available to the scientific community with as few restrictions as feasible, while retaining exclusive use until the publication of major output.