Background and objectives: Considerable rate of restensosis occurs after brachytheraphy. Up to now, there was no long term outcome for brachytheraphy. So we investigated the 10-year clinical follow-up results of intracoronary radiation therapy using a rhenium-188-diethylene triamine penta-acetic acid (188Re-DTPA)-filled balloon system. Methods and Results: After successful catheter-based treatment of either a de novo or restenotic lesion, 185 patients were randomly assigned to either the radiation (N=103) or the control (N=82) group. Irradiation to deliver 17.6 Gy at a depth of 1.0mmin to the vessel wall was carried out after successful intervention. Patients were followed up by telephone or hospital visit at each year and will continue to be followed annually for 10 years. Angiographic follow-up was achieved at total 178 patients. At 10-year follow-up, cumulative target lesion revascularization (TVR) rate was not significantly different between radiation group (n = 101) and control group (n = 77; 26.7% vs. 16.9%; P = 0.148). But the rate of major adverse cardiac events (MACE) including death, myocardial infarction (MI), and TLR were significantly higher in radiation group than control group (30.1 % vs. 17.0%; P = 0.012). And there was no manifestation of hematologic or oncologic illness suspected associated with brachytherapy. Conclusion: Intracoronary radiation therapy mostly in patients with de-novo or in-stent restenosis lesion did not show significant clinical benefit in 10-year follow-up results