This article is based mainly on materials collected in the period between 1994 and 2016 from the journal KUDO published by the Estonian Mordvin Society and reflecting the diverse life of the diaspora. We have also analysed recorded biographical data of Erzya and Moksha people residing in the Republic of Estonia and the archival material of the Estonian Mordvin Society. The article reviews the history of the first settlers, their number, formation of cultural societies and their interaction with other organisations, integration into Estonian society, information about the first Estonian expeditions to the places of the Erzya and Moksha as well as cultural and education ties between Estonia and Mordovia. All this reveals the activities of compatriots, trends in population change in this group, mechanisms of preservation of national identity and the role of Mordvin national and cultural non-profit organisations in the preservation and development of ethnic culture in the Republic of Estonia.