This contribution focuses on the problems of ethnic identity and assimilation processes in minority background, and concentrates on the problems of Slovak minorities. The author. presents the classification of assimilation factors, which he designed on basis of the theoretical aspects of ethnicity. These assimilation factors have a vast influence on members of a minority in minority communities. This approach is guided results of the author's field research and review of relevant literature, especially in the areas of the Republic of Slovakia, Hungary, Romania, Serbia and Croatia. The paper contains new information that can contribute to the theory of assimilation processes. The research of these issues and the outlined factors of ethnic assimilation and their contexts certainly cannot be considered as definitive.