Social parasitic ants exploit the colonies of other ant species, either permanently or temporarily. The permanent parasites are amongst the rarest species of ants, although their hosts may be very common. Due to their rarity and often restricted distribution range, most of them are listed as vulnerable. Filling in the gaps in geographical and host ranges will advance our understanding of the social parasitic lifestyle's origin and evolution. This study reports the first records of the slave-makers Myrmoxenus algerianus (Cagniant, 1968) for Europe (Italy, Sicily) and M. ravouxi (André 1896) for Albania and the inquiline Anergates atratulus (Schenck, 1852) for Malta (Gozo). We also report new localities of Camponotus universitatis Forel, 1890 for Albania and Myrmoxenus gordiagini Ruzsky, 1902, M. kraussei (Emery, 1915) and Anergates atratulus for Bulgaria. Diversity, type of parasite-host relationships, host range, distribution and conservation of social parasitic ant species in Bulgaria are discussed. Although social parasitic ants are still understudied in Bulgaria, they represent 21% of the regional ant fauna.