To evaluate the impact of cilostazol on neointimal hyperplasia after drug-eluting stent (DES) implantation for long coronary lesions, we performed a randomized multicenter prospective study comparing triple antiplatelet therapy (aspirin, clopidogrel, and cilostazol; triple group, n = 250) and dual antiplatelet therapy (aspirin and clopidogrel; standard group, n = 250) for 6 months in patients with long lesions (> or =25 mm) requiring a long DES (> or =32 mm). The primary end point was in-stent late loss at 6-month angiography. The 2 groups had similar baseline clinical and angiographic characteristics. In-stent late loss (0.22 +/- 0.48 mm vs 0.32 +/- 0.51 mm, p = 0.031) and in-segment late loss (0.34 +/- 0.49 mm vs 0.51 +/- 0.49 mm, p = 0.001) at 6-month follow-up angiography were significantly lower in the triple group versus the standard group. There was a trend toward lower rates of in-segment restenosis in the triple group versus the standard group (6.7% vs 11.2%, p = 0.104). Target lesion revascularization (TLR; 2.8% vs 6.8%, p = 0.036) and major adverse cardiac events (2.8% vs 7.6%, p = 0.016), including death, myocardial infarction, and TLR at 9 months were significantly lower in the triple group than in the standard group. At 9 months, the 2 groups had similar rates of stent thrombosis (0.4% vs 0.4%, p = 0.999), death (0% vs 0.8%, p = 0.499), and myocardial infarction (0.4% vs 0.4%, p = 0.999). In conclusion, cilostazol significantly reduced late loss at 6 months after DES implantation and the occurrence of TLR and major adverse cardiac events in patients with long coronary lesions.