The article deals with the phonological status of labial consonants in Avar and their realization patterns in Avar and Russian speech of bilinguals. The comparison of the systems of Russian and Avar consonants is made. The results of our acoustic and expert studies demonstrated, on the one hand, the same occurrence of labio-dental and bilabial consonants in Avar speech and significant speaker-dependent variation of their occurrence - on the other. The study of the negative effects of Avar on Russian speech of the Avar people revealed cases of devoicing resulting from progressive assimilation, various substitutes of bilabial consonants for labio-dental ones, vocalization of consonants that are spelled «в» in different word-positions, elision. For consonants spelled «ф» the number of deviations from the standard realization pattern decreased significantly and was limited to the following types of modifications: the substitute of bilabial [ʍ], [ʍʲ] and [ɸj] for labio-dental [f], [fʲ] and cases of palatal harmony.