This article systematically reviews the literature (313 articles) on language and communication in international students' cross-cultural adaptation in institutions of higher education for 1994-2021. We used bibliometric analysis to identify the most impactful journals and articles, and the intellectual structure of the field. We used content analysis to synthesize the results within each research stream and suggest future research directions. We established two major research streams: second-language proficiency and interactions in the host country. We found inconclusive results about the role of communication with co-nationals in students' adaptation, which contradicts the major adaptation theories. New contextualized research and the use of other theories could help explain the contradictory results and develop the existing theories. Our review suggests the need to theoretically refine the interrelationships between the interactional variables and different adaptation domains. Moreover, to create a better fit between the empirical data and the adaptation models, research should test the mediating effects of second-language proficiency and the willingness to communicate with locals. Finally, research should focus on students in non-Anglophone countries and explore the effects of remote communication in online learning on students' adaptation. We document the intellectual structure of the research on the role of language and communication in international students' adaptation and suggest a future research agenda.