The results of the first phylogenetic investigation of members of the Aulacidae of the world are presented. The main objective was to test the monophyly of the currently recognised genera. In total, 79 morphological characters were scored for a substantial sample of the extant aulacid fauna, including 72 species, as well as 12 outgroup taxa belonging to Evaniidae, Gasteruptiidae, Megalyridae, Trigonalidae, Braconidae and Stephanidae. All zoogeographic regions were represented. The dataset was analysed under different conditions (ordered, unordered, equal and implied weighting). The results under different weighting conditions are not fully congruent and many relationships remain unresolved. However, the analyses demonstrate that the current generic classification of the Aulacidae is not a natural one. There is support for a very large, monophyletic clade which includes all Pristaulacus Kieffer spp. + Panaulix Benoit spp. This suggests a wider generic concept for Pristaulacus, which is redefined and rediagnosed here. As a consequence, Panaulix becomes a junior synonym of Pristaulacus (syn. nov.), and the two described species of Panaulix are transferred to Pristaulacus: Pristaulacus rex (Benoit, 1984), comb. nov., and Pristaulacus irenae (Madl, 1990), comb. nov. The genus Aulacus Jurine was consistently paraphyletic and is not valid as currently defined. Furthermore, we failed to retrieve a consistent topology among the different clades of Aulacus. A satisfactory reclassification of Aulacus, however, requires a much more comprehensive taxon sample and/or additional character data.