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/New Zealand. 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.