This lecture will discuss phonetic, morphological and semantic features of Altaic loanwords present in Yeniseian languages, a rather heterogeneous language family of North-east Asia. Altaic loanwords in Yeniseian are characterized by special features such as syncope, amalgamation, aphaeresis and metathesis. Besides, a separate group of lexemes consists of hybrid words, i.e. lexical elements where one element is Altaic and the other Yeniseian.