A revised diagnosis of Mixobates Thor, 1905, is given, including the proposal to rank this taxon as a separate genus. The species so far published from the palaearctic region are revised. Adults of M. caucasicus Tuzovskij, 1990 are described for the first time and the following synonyms are established : M. uncatus Sokolow, 1930 = M. processifer Thor, 1905 ; M. lundbladi Schwoerbel, 1957 = M. incurvatus Láska, 1954. The latter species is for the first time recorded from the Mediterranean area. Four new species are described : M. acutidentatus, M. brachypalpus and M. uncatellus from Russia, and M. maghrebinus from Morocco. A dichotomic key for the determination of the palaearctic species is presented.