The objective of this study was to determine the long-term major adverse cardiac events (MACE) in patients treated with intracoronary brachytherapy (ICBT) for coronary in-stent restenosis (ISR). ICBT was commonly used to treat coronary ISR prior to the availability of drug-eluting stents (DES). The long-term outcomes of ICBT for ISR remain unknown. Six hundred and eighty consecutive patients who underwent ICBT treated for ISR between September 1998 and April 2005 were included in the study. Clinical and angiographic data were collected and the long-term MACE were measured for all-cause death, myocardial infarction (MI), and target vessel revascularization (TVR) at 10-year follow-up. Patients were 63 ± 11 years old (66% male). The majority of patients were treated with a bare metal stent 670/680 (99%) prior to ICBT. Significant baseline clinical findings include high incidence of smokers 479/680 (70%), hyperlipidemia 638/680 (94%), and multivessel disease 526/680 (77%). The majority of target lesions were diffuse 407/680 (60%), and either in the left anterior descending 258/680 (38%) or right coronary artery 215/680 (32%). At 10-year follow-up, the rate of death was 25%, MI was 22.4%, and TVR was 48%. MACE at 10-year follow-up following ICBT for ISR indicates steady rate of death and MI and declining rate of TVR after 5 years.