This chapter examines how Indigenous language resources were mobilized by some Indigenous teachers in the state of Acre, western Amazonia, as they revitalized their linguistic heritage and endeavored to represent it in a new and positive light, in response to the new circumstances ushered in by the Brazilian Constitution of 1988. The starting point for the pro-Indigenous languages movement orchestrated by the Indigenous teachers of Pro-Indigenous Commission of Acre (CPI-Ac) was their efforts to reassert the value of the languages and to give them new prestige in the minds of their speakers. Writing about Indigenous teachers in Andes, Hornberger has noted that it is during their professional training and development that many Indigenous teachers have been able to critically reflect upon their own Indigenousness. Through their teacher education and pedagogical experiences, Indigenous teachers enrolled in the CPI-Ac linguistic revitalization program have had a chance to reflect on and rethink what it means to be Índio in contemporary worlds they inhabit.