The article outlines the ecolinguistic principles and strategies of teaching a foreign language as a language of interethnic communication. The ecolinguistic approach assumes that teaching a foreign language as a language of interethnic communication should promote communication around the world, without violating the original linguistic traditions of nations, nationalities and ethnic groups, provide linguistic and cultural diversity, a culturally rich, but united world. In this regard, a foreign language is also intended to serve the needs of host cultures, to preserve and emphasize their uniqueness. As a language of international communication, a foreign language is seen not as a full-fledged linguoculturally filled language, but as a code for the transmission of personal and national linguoculturally conditioned messages. This kind of code should adapt to the needs and requirements of the world community, borrowing designations with appropriate meanings from national languages, and not vice versa. Rather than level cultures and civilizations, we see its role as reflecting their diversity. Ecolinguistic strategies for teaching a foreign language as a language of interethnic communication proposed, in line with which it is deemed desirable for foreign language curricula to represent: 1) to the maximum — global issues, world heritage, history/modernity/future, 2) extensively — modernity, history, culture of host cultures, 3) to a moderate degree — modernity, history, culture of the country of a foreign language (10–20 % of the educational material). When teaching a foreign language, traditional language pedagogy is preferred, the linguocultural method combined with immersion are deemed not quite ecolinguistic because of foreign acculturation. It is welcome though when teaching the national/native language to create a strong cultural identity (inculturation) and immunity to foreignization. In TEFL, immersion can be used, but without acculturation. Excessive branding of foreign realities and personalities as part of foreign acculturation is not believed to be sustainable. Foreign language textbooks should be politically correct and tolerant, especially with regard to facts, history, values, personalities of the host culture; traditional moral and ideological conclusions should ensue from the texts. The national/native language should be used as a rightful metalanguage of explanation when comparing cultural phenomena. It is advisable to write and publish foreign language textbooks by the authors of the host culture.