This study provides the first record of Bathysolen nubilus (Fallen, 1807) for the Republic of Buryatia (Russian Federation) and extends the known distribution of this species eastward in the Palaearctic region. Bathysolen nubilus is the only species of its genus that occurs in Eurasia. Specimens of B. nubilus were captured in dry grass meadows and forest edges located along the lower reach of the Selenga River. Data and figures of B. nubilus for the recognition of the species, as well as a map of collecting localities, are presented.