StrongylognathusMayr, 1853 is a Palaearctic genus, comprising 25 ant species and one subspecies, all permanent social parasites, infesting colonies of various species ofTetramoriumMayr, 1855. They have patchy distribution throughout their areas and most of them are very rare and listed as vulnerable.The taxonomy of theStrongylognathus huberigroup needs thorough revision and the results presented below can be considered as preliminary.Four species of the socially parasitic ant genusStrongylognathus(S. karawajewiPisarski, 1966,S. huberi dalmaticusBaroni Urbani, 1969,S. aferEmery, 1884 andS. italicusFinzi, 1924) are recorded for the first time from Bulgaria and, together with the previously-knownS. testaceusandS. bulgaricusstat. rev., their total number reaches six. The taxonomic position and geographic distribution of all species are discussed and a Key for their identification, based on worker caste, is compiled.