The present thesis is an attempt at a grammatical description of Tundra Yukaghir (TY), based on a variety of primary data including those collected by the author during three field trips from 2009 till 2012.TY is a highly endangered minority language spoken in north-eastern Russia. It has slightly more than 60 speakers, none of whom are strictly monolingual. People under the age of 50 normally do not use it in their daily communication. TY is most probably related to the Uralic language family.After discussing genetic and socio-linguistic issues, the thesis successively presents TY phonology, morphology, syntax and the organization of information structure. Some of the more conspicuous properties of TY are the combination of the relatively high degree of syllable complexity and TY being a head-final language, a five-way system of demonstrative pronouns, an extremely small class of basic adjectives, a formal marking of (in)transitivity as well as a formal de-transitivization under negation, a reach aspectual and reduced (future vs. non-future) tenses system, an almost complete lack of modal verbs, no agreement between the dependent and its head in a NP, an ergativity split based on the pragmatic function of core arguments and the person hierarchy, four copular devices to form non-verbal predicates, semi-transitive clauses and adjunct-oriented participles, a sophisticated focus system.This thesis is of interest for a broad circle of linguistically motivated readers, especially typologists and those occupying themselves with Uralic languages.