© the author(s). This article deals with the analysis of the morphological assimilation of Arabic loanwords into Tatar, Altai language family, and Swahili, Bantu language family. The urgency of this review is caused by the fact that the formation of both Tatar and Swahili was influenced by Arabic, which had profoundly influenced them in religious, scientific, cultural and economic aspects. In this paper we apply the comparative approach that is aimed at finding isomorphic and allomorphic features in the languages studied and identifying their peculiarities in the process of Arabic vocabulary assimilation. The morphological assimilation of Arabic loanwords into these languages is realized by verbal nouns, participles, nouns denoting place and action. One of the isomorphic features of the recipient languages is the absence of the category of gender both in Tatar and Swahili; among the allomorphic peculiarities are postposition of adjectives after nouns in Swahili and the use of compound verbs with Arabic nouns as their stems in Tatar. The results of the research will contribute to the loanword studies in these unrelated languages.