The first phylogenetic analysis of the sawfly family Cimbicidae is presented. The phylogeny within Cimbicidae is examined with over 60 morphological characters coded for 16 species from 13 of the currently recognized 16 genera. The characters are from external morphology of the adults as well as male genitalia. Homoplasy in the dataset is very low. In the resulting most parsimonious cladograms, all four subfamilies and one of the cimbicid tribes, Trichiosomini, are monophyletic. The most basal split within Cimbicidae is between the South American subfamily Pachylostictinae on one hand and the remaining three subfamilies on the other. In the latter group, Coryninae is sister to Abiinae+Cimbicinae. No nomenclatural changes are proposed.