AbstractXanthopygina is a group of colourful, neotropical rove beetles (Staphylinidae) comprising 28 genera and more than 350 species. While many genera are found on rotting fruits, carrion, dung and mushrooms, several taxa have evolved associations with social insects. Previous phylogenetic analyses have used only a subset of genera and were based solely on molecular data. In this paper, we performed Bayesian and maximum likelihood phylogenetic analyses of all known genera, including three potentially new genera, based on molecular (4,797 bp) and morphological (91) characters. Our results reaffirmed the monophyly of the subtribe and divided it into eight major lineages: the Elmas, Gastrisus, Isanopus, Ocyolinus, Plociopterus, Smilax, Trigonopselaphus and Xanthopygus groups. We hypothesized that myrmecophily evolved once in the common ancestor of the Smilax group, and that sphecophily possibly evolved twice, in the Trigonopselaphus and Xanthopygus groups.