This study sought to evaluate the effect of cilostazol in preventing restenosis after successful percutaneous transluminal coronary angioplasty (PTCA) in 68 patients35 patients received cilostazol immediately after PTCA and 33 patients received aspirin or ticlopidine. Repeat coronary angiography was performed 4 to 6 months after PTCA and the incidence of restenosis was significantly lower (17%) in the cilostazol group than in the non-cilostazol group (40%) (p < 0.05), which indicates that cilostazol has the potential to prevent restenosis after PTCA.