and of the Amazon region in general. Linguists expect that the majority of these peoples will cease to exist as distinct language communities during the coming decades. The present work is intended as a contribution to the documentation and preservation of the languages of the Amazon basin. In this respect, Kwaza has represents an especially urgent case in view of its undetermined classification, the lack of documentation and its endangered status. This work is based on the author¿s personal fieldwork conducted between 1995 and 2002, and it consists of three parts. Part I contains a thorough description of the phonology and morphosyntax of the language and a concise overview of its social, cultural and historical context. Part II contains a diverse selection of transcribed and translated texts with interlinear morphological analyses. Part III is a dictionary of Kwaza, including many examples and an English- Kwaza register. This complete description is of interest to linguists in general, scholars of South American languages in particular, and anthropologists and historians interested in the Guaporé region.