[en] During the last years coronary endovascular brachytherapy has been extensively explored as a new treatment to prevent restenosis after percutaneous coronary interventions. While clinical and physical aspects of such treatments are addressed in literature, there is little information available on radiation protection and radiation safety aspects. In this paper we estimate the radiation risk for the patient using analytical methods and Monte Carlo calculations for three delivering systems currently used in clinics. Additionally, radiation risk to personnel involved in such treatments is investigated. For gamma emitting sources the radiation exposure to patients is in the order of magnitude of the exposure due to diagnostic angiography. Doses to organs at risk when applying beta emitting sources are significantly lower. Measured doses for the intervention personnel are consistent with the estimated whole body dose. They are smaller than 7,5 μSv per intervention, which is a dose much less than 0,1% of the annual radiation worker's Maximum Permissible Dose (MPD) recommended by EC regulations, and less than 1% of the general public's MPD. (author)