Aims: Increased major adverse cardiac events (MACE) beyond six months after intracoronary beta radiation brachytherapy (IRBT) are a major concern. The aim of this study was to evaluate the 10-year clinical outcome after IRBT. Methods and results: From 1997 to 2002, 301 consecutive patients treated with IRBT were included prospectively, whereafter 602 control patients treated with conventional percutaneous coronary intervention (PCI) were matched by propensity score methodology. MACE was defined as all-cause death, any myocardial infarction or any revascularisation. Median follow-up duration was 9.7 years. Mortality rates in both groups were similar. Cumulative 5-month, 2-, and 10-year MACE-free survival rates of IRBT patients were 89%, 56% and 29%, respectively, while those of the control patients were 90%, 76% and 52%, respectively (p<0.001). The difference in the MACE rate was mainly driven by target vessel revascularisation (TVR) (p<0.001). Furthermore, two or more repeat TVRs were needed in 12% of IRBT patients and in only 6% of control patients (p<0.01). Adjusted hazard ratios for IRBT-associated all-cause mortality and MACE were 1.0(95% CI 0.7-1.5) and 1.8(95% CI 1.5-2.2), respectively. Conclusion: IRBT was associated with increased MACE between five months and two years of follow-up, mainly driven by repeat revascularisations. Similar event rate after two years indicate that there were no very late adverse effects related to IRBT.