Antiplatelet agents, such as aspirin, clopidogrel, and cilostazol, are essential for the treatment and prevention of cardiovascular, cerebrovascular, and peripheral vascular diseases. A 53-year-old male with aspirin hypersensitivity developed dizziness, which was caused by severe stenosis of the left vertebral artery. Clopidogrel was administerted, but discontinued due to generalized urticaria and angioedema. As an alternative drug, cilostazol was administered, but discontinued again because of the same adverse reactions. Desensitization was planned as other alternative antiplatelet agents were not available. Initially, aspirin desensitization was successfully performed. One day after aspirin desensitization, clopidogrel desensitization was sequentially done successfully. After a few months, cilostazole desensitization was performed. During the follow-up period, he had to stop aspirin and cilostazol twice to prevent the risk of bleeding after a procedure and an operation. After discontinuing medicines, sequential desensitization of aspirin and cilostazol was successfully performed. Physicians should be aware that drug hypersensitivity could be induced by various kinds of antiplatelet agents and that desensitization could be the treatment of choice unless alternative medicines are available. Allergy Asthma Respir Dis 2016:4:374-377)