This thesis examined ethnic federation with the politics of indigenity and its consequences in Bullen Woreda of Benishangul-Gumuz. Particularly, the thesis by drawing upon qualitative methodology analyzed the influence of ethnic based federal system in inter-ethnic relations that ensued in security challenges and causes of eviction that displaced many people in Benishangul – Gumz Region, Ethiopia, in 2013. It argues the association of ethnic groups to a portion of Ethiopia has brought the feeling of owner and non-owner, indigenous and non-indigenous, native and non-native, etc. An ethnic regional border has become new conflicting grounds in different parts of Ethiopia, which is against the age-old population mix and communality. This study addresses the connection of ethnic based federalism with the problem of non-indigenous eviction taking an illustrative case in Benishangul-Gumuz Region. The study tries to identify the causes of eviction that show the general picture associating to ethnic structure employing Purposive and Snowball sampling techniques accompanied with pertinent documents. It reveals ethnic federal structure has influenced regional politics of Ethiopia, and factors that fall under political, historical and socio-economic catalogs were the major causes contribute to expulsion. The study ends up with drawing summary, conclusion, recent developments, future scenarios and recommendations.