This work contains a descriptive grammar of Mamaindê, a Northern Nambikwara language of west central Brazil. The Mamaindê language is spoken by some 250 people, located in four communities. While bilingualism in Portuguese is rapidly gaining ground, the spoken vernacular has so far been able to preserve critical domains and thus maintain a healthy level of vitality. There are many signs, however, of both cultural and language shift, indicating that this language may be on the edge of endangerment. The first chapter includes a broad overview of the culture and history of the Mamaindê people. A connection between language and culture is stressed at the outset, with examples of this relationship being given at significant points throughout the work. Subsequent chapters address the areas of Phonology, Morphology, and Syntax, the last of which also includes a section on Discourse. Data is offered which should be of interest to those involved in the research of Nambikwara languages, Amazonian linguistics, and linguistic typology. Specific topics which are relevant to current theory include an eclectic view of feature geometry, the analysis of pre-oralized nasal segments, coda licensing, stress in lexical strata, tone sandhi, evidentiality, endearment terms, emotives, noun classifiers, the impersonal construction, and the presence of low and high registers in an Amazonian language.