Esperanto seems to share several basic characteristics with minority languages. Tendencies regarded as basic features of the Esperanto community, such as voluntariness, non-ethnic composition, non-territorial distribution or the “internal idea“ can be observed also among minority languages. It can thus be argued that phenomena and tendencies that can be observed in the case of Esperanto are even clearer or more pronounced in the case of the (other) minority languages, and vice versa. The two can function as “mirrors“ for one another. Not only their aims to promote multilingualism, but also the current opportunities and problems that these strikingly similar linguistic communities face, appear to make cooperation useful and open new prospects for comparative research.