The Book of Abstracts invites you to get acquainted with the issues discussed at the 8th international scientific conference Sustainable Multilingualism 2025 (SM25), organized by the Institute of Foreign Languages at Vytautas Magnus University, Lithuania, and the Language Teachers’ Association of Lithuania, held in Kaunas, May 29-31, 2025. The primary objective of SM25 was to provide a common platform for researchers, language policy makers, language teachers, students, and anyone interested in discussing and sharing their expertise on key issues of multilingualism, plurilingual competence development, and language education.