Background and Objectives: New stent implantation during intracoronary brachytherapy is strongly discouraged due to the high risk of late thrombosis. However, new stent implantation is inevitable in some cases because of inadequate results of balloon dilatation or major dissections. Long-term follow-up results of newly implanted stents during radiation therapy are not well-known. We performed this study to evaluate the long-term clinical outcomes of new stent implantation during intracoronary radiation therapy and to determine the prognostic factors in these patients. Subjects and Methods: In the Seoul national university Post-Angioplasty RhEnium irradiation(SPARE) trial, patients with significant stenotic lesion in native vessel were first treated with conventional catheter-based technique and then randomized to either 棺-radiation(RG) or control group(CG). Radiation was performed with 188-rhenium-filled balloon catheter system. From 1999 to 2001, new stent implantation was performed in 58 and 56 patients in RG and CG, respectively. Clinical and angiographic follow up data of these patients were analyzed. Results: Baseline clinical and angiographic characteristics were not different between the 2 groups. In RG, short-term angiographic restenosis rate was 28.6%(14/49). Late total occlusion was found in 5 patients. At 2 year clinical follow up, major adverse cardiovascular events(MACE) were observed in 15 patients(death:1, myocardial infarction:2, target vessel revascularization:12) in RG. In 5 patients, MACE occurred at more than 1 year after brachytherapy. Independent predictors for MACE in RG were major dissections(���type C) after stent implantation(棺=29, p=0.01) and longer administration of dual antiplatelets(aspirin + clopidogrel/ticlopidine, >6months, 棺=0.1, p=0.04). Two year MACE rates were not different between the 2 groups(RG: 26% vs. CG: 25%). Conclusion: Stenting during intracoronary radiation therapy seems to be ineffective in reducing long-term event rates. When new stent implantation is ineveitable during radiation therapy, extreme attention is required not to make a dissection and long-term dual antiplatelet treatment should be followed after stent implantation.