This study aimed to resolve the differences in the two currently used classifications of Mutillidae, which differ in many respects. Cladistic analyses of 101 genera and subgenera of Mutillidae (represented by females of 253 species and males of 260 species) and four outgroups (pepsine Pompilidae, anthoboscine Tiphiidae and both fedtschenkiine and sapygine Sapygidae) based on 230 morphological characters treated in various ways, produced most-parsimonious trees which were in broad agreement but differed in many details. Evaluation of these results led to the proposal of a compromise tree which reflected each proposed taxon as monophyletic, while trying to keep disruptions to the current classifications to a minimum. The result differs from both previous classifications, and proposes the recognition of eight subfamilies: Myrmosinae (with the tribes Kudakrumiini and Myrmosini), Pseudophotopsidinae, Rhopalomutillinae, Ticoplinae (with the tribes Smicromyrmillini and Ticoplini), Sphaeropthalminae (with the tribes Sphaeropthalmini, Dasymutillini trib. n., and Pseudomethocini with the subtribes Euspinoliina subtrib. n. and Pseudomethocina), Myrmillinae, Dasylabrinae (with the tribes Apteromutillini trib. n. and Dasylabrini) and Mutillinae (with the tribes Ctenotillini trib. n., Smicromyrmini, Mutillini with the subtribes Ephutina and Mutillina, and Trogaspidiini). Notably, Myrmosinae were consistently strongly supported as monophyletic with the remaining Mutillidae (disagreeing with a recent molecular analysis), and thus retained as a mutillid subfamily. The placements of all currently valid genera and subgenera in the proposed classification are provided.