This article discusses the delicate relationships when demarcating the concepts of endonym and exonym. In addition to problems connected with the study of transnational names (i.e., names of geographical features extending across the territory of several countries), there are also problems in ethnically mixed areas. These are examined in greater detail in the case of place names in Slovenia and neighboring countries. On the one hand, this raises the question of the nature of endonyms on the territory of Slovenia in the languages of officially recognized minorities and their respective linguistic communities, and their relationship to exonyms in the languages of neighboring countries. On the other hand, it also raises the issue of Slovenian exonyms for place names in neighboring countries and their relationship to the nature of Slovenian endonyms on their territories. At a certain point, these dimensions intertwine, and it is there that the demarcation between the concepts of endonym and exonym is most difficult and problematic.