Abstract: BACKGROUND: Although drug-eluting stents (DES) are widely used today, bare metal stents (BMS) are still frequently employed. We investigated the utilization and clinical outcomes of BMS implantation since we first began using DES. METHODS: The clinical course following percutaneous intervention with de novo implantation of BMS was studied beginning in July 2004, when sirolimus-eluting stents (SES) were first used in our hospital, to August 2006. Outcomes following BMS and SES implantation were compared. RESULTS: BMS implantation was carried out in 160 lesions and SES implantation in 242 lesions. Follow-up coronary angiography was performed for 208 lesions (78 lesions in which BMS were implanted and 130 lesions in which SES were implanted) within 1 year. There were no significant differences in patient characteristics between the SES and BMS groups. Regardless of the reason for BMS implantation, the rates of in-stent restenosis and target lesion revascularization were higher in the BMS group than in the SES group. However, the rate of in-stent restenosis and target lesion revascularization of BMS in lesions with a diameter of 4.0mm or greater was 0%. CONCLUSIONS: In order to reduce the risk of in-stent restenosis and target lesion revascularization, we recommend implantation of BMS with a diameter of 4.0 mm or greater or SES unless it is contraindicated.