The concept of "Exclusivism" is considered to represent one of the most characteristic features of International Nuclear Law. This concept is reflected by regulating matters of uses of nuclear energy and ionising radiation exclusively by distinct principles, that govern legal relations arising in these matters. The concept of "Exclusivism" has been widely reflected in the provisions of international conventions, which have been adopted since the 1960s. This article aims to revisit this concept, taking the most recent developments in international and European law into regard. The article is dealing with the reasons and origins of the concept of "Exclusivism" in International Nuclear Law, with reflections of this concept in existing international treaties and at last but not at least, with most recent tendencies, that aim at jeopardising this concept., Jakub Handrlica., and Obsahuje bibliografické odkazy