This article explores mother tongue awareness among several Brazilian Amerindian societies in contrast with the perception of the importance of the vernacular according to policy makers and academics. The perception of the vernacular as important is discussed in the light of continuing debate among Brazil's educators concerning appropriate educational intervention within traditional societies. Two case studies are presented. One illustrates the Jarawara people's appropriation and use of writing in their own language, even as academics were debating the pros and cons of literacy for an oral society. The Jarawara incorporated writing into their culture in an unique manner, communicating with each other in ways that oral communication inhibited for cultural reasons. The second illustrates the Xerente's perception of their written language as a means of cultural affirmation and resistance in opposition to the majority culture. These two cases represent opposite poles on a continuum in the ongoing struggle of traditional societies to find acceptance and equality in Brazil's multicultural mosaic. The studies reveal cultural, sociolinguistic and human factors which must be considered by policy makers if the practical educational needs and aspirations of minority groups are to be respected. Clearly, there are implications for mother-tongue language issues worldwide. (Contains 5 notes.)