Abstract Total evidence analysis, based on a combination of morphological and ecological characters with two mitochondrial sequences (cytochrome c oxidase subunits I and II) and one nuclear (elongation factor-1α) sequence, provides a new phylogeny of the uniquely obligate ant parasitic Phengaris–Maculinea butterflies. The clade, including all species of Maculinea and Phengaris, is very stable and well supported. However, various analyses suggest that either Phengaris or Maculinea is not monophyletic with regard to the other, which necessitates generic reclassification of the clade. Application of the diagnostic and monophyletic ‘phylogenetic’ species concepts leads to species-level reclassification, including ten species (P. alcon comb.n. including ‘P. rebeli’, P. daitozana, P. albida, P. atroguttata, P. kurentzovi comb.n., P. nausithous comb.n., P. teleius comb.n., P. arion comb.n., P. arionides comb.n., P. takamukui comb.n.) and one unresolved metaspecies (‘P. cyanecula’ comb.n.) in four monophyletic species groups. The existence of further or additional cryptic species is possible within P. nausithous and P. teleius. Maculinea Van Eecke, 1915 syn.n. is considered a junior synonym of Phengaris Doherty, 1891.