Background: Adjunctive Cilostazol (Pletaal짰) to dual antiplatelet therapy (triple antiplatelet) is associated with favorable clinical outcomes in selective patients (pts) such as acute coronary syndrome. However, the data of triple antiplatelet therapy in chronic stable angina pts undergoing elective percutaneous coronary intervention (PCI) with drug-eluting stent (DES) in real-world is limited. Method: A total of 1158 consecutive pts except acute myocardial infarction (AMI) undergoing elective PCI with DES from April 2006 to February 2009 were enrolled. Usage of adjunctive Cilostazol was depending on physician���s discretion and administered by 200mg post-loading and then 100mg bid for at least one month. Clinical and angiographic outcomes at 6 months were compared between triple and dual antiplatelet group. Results: Out of 1158 pts, 435 pts (37.57%) received adjunctive Cilostazol. Triple group had worse angiographic characteristics including more bifurcation (36.3% vs. 29.2%; P=0.002), left main (8% vs. 2.4%; P<0.001), Diffuse long (30.8% vs. 24.9%; P=0.004) and Ostial lesions (22.1% vs. 13.8%; P<0.001). Longer stent (24.75짹6.59 vs. 24.02짹6.25; P=0.073) implantation was more common in triple group. Despite the higher risk subset of pts in Cilostazol group,incidence of stent thrombosis and angiographic outcomes were similar between two groups. Although it was not statistically significant, there were 6 stent thrombosis (2 subacute,4 late) in Dual group whereas only 1 subacute stent thrombosis in Triple group (Table). Conclusion: Despite of worse baseline characteristics, Triple antiplatelet therapy provided similar midterm clinical and angiographic outcomes compared with those of dual antiplatelet therapy group.