Background: In-stent restenosis has continued to limit the long-term success of stent implantation, especially in small coronary artery. Drug-eluting stent (DES) was previously demonstrated to reduce neointimal hyperplasia significantly. Objective: The aim of this study is to clarify the safety and effectiveness of the DES in treating small coronary arteries in real-world compared to bare metal stent (BMS). Methods: From Jan. 2002 to Jan. 2005, 189 patients (204 lesions) underwent percutaneous coronary intervention (PCI) with 2.50mm or 2.75mm sized stent. Patients were divided to BMS and DES groups. The clinical characteristics, PCI results and clinical outcomes were analyzed. Results: More than 6 months clinical follow-up was available in 92.2%. Angiographic follow-up was available in 45.9%. See as a following table. Conclusions: PCI in small coronary artery is at very high risk of restenosis. In these patients, the DES dramatically reduces the risk of major adverse cardiac events and angiographic restenosis.