The aim of this study is an empirical analysis of the construction of ethnic identity of Slovaks living in Hungary and Hungarians living in Slovakia. As a consequence of historical and political changes, these two communities assumed a minority status, while their national countries (mother countries) remained the neighbouring countries. On the basis of research conducted in Hungary and Slovakia, the authoress analyses both minorities from the point of view of the ethnic construction and its possible development. On the basis of ethnic characteristics of Slovaks living in Hungary and Hungarians living in Slovakia (in the extent of the chosen analysis) presented here she can state that the ethnic identity construction of the examined minorities differs from each other. It is evident that they have different ethnic self-identity due to the subjective and objective factors which, after all, influence the maintenance and the future construction of ethnic identity. In spite of the already mentioned difference, the findings of this research show that the ethnic construction of the two minorities has one common characteristic: both minorities consider the maintaining and development of the ethnic identity as the most important, mainly through the strengthening of the mother language. They are aware that the mother language is the most important element of ethnic construction, regardless of the position of their community in existing society.