The topic of this thesis is the phenomenon of UFO communities: development, beliefs and social implications. The idea of the existence of intelligent life outside of planet Earth, testimonies of unidentified flying objects, and encounters with beings from other planets have been part of popular culture since the late 1940s. Numerous films, series, shows, books, songs deal with this topic, and there is a noticeable increase of organizations of people who participate in discussions and research on this phenomenon. Some of these organizations publish magazines and organize large annual gatherings, which is an indicator that these are groups that are connected to things that they have in common, that give them a sense of belonging, and based on that we can call them a community. Members of this community often invest in serious research, critical approach and detailed analysis in the study of UFO phenomena. Given that the community is one of the basic concepts of sociology, this paper will try to address the reasons and context of origin of UFO communities, show the beliefs of its members and social implications, mostly because of insufficient research of unconventional topics in Croatia. Within the qualitative methodology, semi-structured interviews of community members in Croatia will seek to gain a deeper insight into this phenomenon.