The late Miocene locality Hadjidimovo in Southwestern Bulgaria has yielded a huge collection of mammalian fossils, including a complete skull of MachairodusKaup, 1833, first described (in Bulgarian) by Kovachev (2002). We re-describe it here, compare it with other Machairodus, and review the evolution of the genus. We conclude that the transition from M. aphanistus (Kaup, 1832) to M. giganteus (Wagner, 1848) is gradual and mosaic, that assigning these species to different genera fails to reflect this relationship, and that the Hadjidimovo skull represents a rather late evolutionary stage of this lineage.