This study compared the safety and efficacy of cilostazol and clopidogrel after coronary stenting. Patients (n = 689) who underwent successful stenting were randomly assigned to receive cilostazol (group 1, n = 344, 612 lesions) or clopidogrel (group 2, n = 345, 628 lesions). The incidence of subacute stent thrombosis or major adverse cardiac events, including death, myocardial infarction, and target lesion revascularization within 30 days (2.6% in group 1 vs 2.0% in group 2, p = 0.61) and side effects that required cessation of study drug (0.6% each) did not differ statistically between groups. These results indicate that cilostazol is as safe and effective as clopidogrel in preventing thrombotic complications after stenting.