A study of the Uralic and Yukaghir protolanguages, and an account of the history of Uralo-Yukaghir research, seeking to determine whether Uralic and Yukaghir are genetically related entities. The authors examine more than 350 lexical comparisons of Yukaghir with at least two Uralic subbranches, and attempt to establish phonetic correspondences between the protolanguages. The similar typology, word order, relatively high number of common pronouns, some numerals, grammatical parallels, and very similar phonological systems, are all taken into account to support the existence of a hypothetical Proto-Uralo-Yukaghir language. A study of the Uralic and Yukaghir protolanguages, and an account of the history of Uralo-Yukaghir research, seeking to determine whether Uralic and Yukaghir are genetically related entities. The authors examine more than 350 lexical comparisons of Yukaghir with at least two Uralic subbranches, and attempt to establish phonetic correspondences between the protolanguages. The similar typology, word order, relatively high number of common pronouns, some numerals, grammatical parallels, and very similar phonological systems, are all taken into account to support the existence of a hypothetical Proto-Uralo-Yukaghir language.