This article considers instances of biliterate educational practice in contexts of indigenous language revitalization involving Quechua in the South American Andes, Guarani in Paraguay, and Maori in Aotearoa/NewZealand. In these indigenous contexts of sociohistorical and sociolinguistic oppression, the implementation of multilingual language policies through multilingual education brings with it choices, dilemmas, and even contradictions in educational practice. I consider examples of such contentious educational practices from an ecological perspective, using the continua of biliteracy and the notion of voice as analytical heuristics. I suggest that the biliterate use of indigenous children's own or heritage language as medium of instruction alongside the dominant language mediates the dialogism, meaning-making, access to wider discourses, and taking of an active stance that are dimensions of voice. Indigenous voices thus activated can be a powerful force for both enhancing the children's own learning and promoting the maintenance and revitalization of their languages.