Despite the recent attention given to multicultural and bilingual teaching, several studies indicate that teacher education programmes in South African higher education institutions continue to instruct pre-service Mathematics teachers in Foundation Phase predominantly in English. This poses difficulties for learners when they start teaching in schools. Thus, this study examines the strategies employed by Mathematics teacher educators (university lecturers) in preparing Mathematics student teachers (teacher trainees) for mother-tongue-based bilingual teaching in the Foundation Phase. Underpinned by an interpretivist paradigm, this study employed a qualitative research approach and a case study design. Twelve participants from two public universities in the Eastern Cape province of South Africa were purposively selected for this study. Data were gathered through semi-structured interviews, formal observation, and document review, and the collected data were analysed thematically. The research findings revealed that, although there is no one-size-fits-all approach to training Mathematics student teachers for bilingual teaching, the major strategies employed by Mathematics educators include organising collaborative lesson planning sessions, incorporating technology and multimedia into lesson planning, providing resources and materials in the mother tongue, and code-switching. Based on its findings, the study concludes that using these approaches can equip student teachers with the essential language skills and cultural awareness needed to provide their students with a fair and inclusive Mathematics learning environment, which, in turn, helps Mathematics student teachers become effective educators for bilingual learners.