Abstract Leptophlebiidae is among the largest and most diverse groups of extant mayflies (Ephemeroptera), but little is known of family-level phylogenetic relationships. Using two nuclear genes (the D2 + D3 region of 28S ribosomal DNA and histone H3) and maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI), we inferred the evolutionary relationships of 69 leptophlebiids sampled from six continents and representing 30 genera plus 11 taxa of uncertain taxonomic rank from Madagascar and Papua New Guinea. Although we did not recover monophyly of the Leptophlebiidae, monophyly of two of the three leptophlebiid subfamilies, Habrophlebiinae and Leptophlebiinae, was recovered with moderate to strong support in most analyses. The Atalophlebiinae was rendered paraphyletic as a result of the inclusion of members of Ephemerellidae or the Leptophlebiinae clade. For the species-rich Atalophlebiinae, four groups of taxa were recovered with moderate to strong branch support: (i) an endemic Malagasy clade, (ii) a Paleoaustral group, a pan-continental cluster with members drawn from across the southern hemisphere, (iii) a group, uniting fauna from North America, southeast Asia and Madagascar, which we call the Choroterpes group and (iv) a group uniting three New World genera, Thraulodes, Farrodes and Traverella. Knowledge of the phylogenetic relationships of the leptophlebiids will aid in future studies of morphological evolution and biogeographical patterns in this highly diverse and speciose family of mayflies.