The first Russian record of fossil bristlemouth from the Middle-Late Miocene of Sakhalin Island (Kurasi Formation) is reported and described as a new species, Cyclothone mukhachevae (Pisces: Gonostomatidae). The new Miocene species is similar in pigmentation, proportions, and metric characters to the group of Recent black bristlemouths. The short base of the dorsal fin resembles that of living C. atraria. The new species differ from the latter in the somewhat fewer teeth in the maxilla and the posteriorly displaced beginning of the dorsal fin base relative to the beginning of the anal fin (vs. at the same level). The geographical range of C. atraria is closest to the locality of C. mukhachevae among other species of Cyclothone. This indirectly corroborates the assumption that morphological similarity of the two species results from their close relationship. Keywords: Teleostei, Gonostomatidae, new species, Middle-Late Miocene, Sakhalin Island DOI: 10.1134/S0031030115020045