This work contains a comprehensive description of Kwaza, which is an endangered and unclassified indigenous language of Southern Rondonia, Brazil. The Kwaza language, also known in the literature as Koaia, is spoken by around 25 people today. Until recently, our knowledge of Kwaza was based on only three short word lists, from 1938, 1943 and 1984. Like the language, the culture and the history of its speakers are undocumented. The Kwaza people as an ethnic group have been decimated by increasing ecological, physical, social and cultural pressure from Western civilisation since contact in...