This article examines the issue of radioactive waste in Northeast Asia from a regional environmental security complex perspective. First, the study tries to determine if it is proper to examine the issue from a "regional" and "security" perspective. It then discusses the radioactive waste management systems of the countries in Northeast Asia, and assesses the status of the regional radioactive waste security complex based upon two cases of radioactive waste dumping, as well as the prospects for regional cooperation. The article concludes that the emergence of proposals on the safe management of radioactive wastes and efforts to promote cooperation on nuclear affairs implies that common interests do exist and that mutual gains can be realized among Northeast Asian countries from regional cooperation. However, numerous obstacles must be overcome before an effective regional institution can be established.