The author of the article focuses on a topic that has not been sufficiently studied by experts and analysts – the role of the Shiite factor in the religious and political life of Muslim communities in Europe. This situation is partly due to the small size of the Shia communities and the increased loyalty of most of their members to the authorities of the host country in comparison with the Sunni communities, which are much more numerous and have a longer history of coexistence with the indigenous population on the European continent. As part of the study of the problems of Islamic radicalism and extremism in Europe, the previous issues of the Bulletin examined in detail the structure, system and features of the activities of the cells and organizations of the international association of the Sunni Muslim Brotherhood there. They are almost openly patronized by such states as Turkey and Qatar, and Saudi Arabia, the UAE, Egypt and a number of other Arab states are trying to expose in the eyes of Europeans and limit the influence of «brothers» in the Old World. Behind the Shiite radicals in Europe are, of course, Iran and groups like Hezbollah sponsored by it, as well as international organizations of Shiite Muslims. The author notes the strengthening of radical sentiments in the Shiite communities of European countries. This is due not only to the efforts of Iran’s paramilitary structures, extremist Hezbollah, but also in many respects – paradoxically – the rapprochement between Sunni and Shiite radicals on European territory.