Partial DNA sequence data from the mitochondrial DNA (mtDNA) cytochrome oxidase I and II genes were used to construct a molecular phylogeny based on representative species from 10 of the 20 genera of Sesiidae. Maximum likelihood, maximum parsimony, and Bayesian analysis were utilized. Sequencing of a 606-base pair region of the mtDNA cytochrome oxidase I (COI), tRNA leucine, and COII gene revealed 271 polymorphic sites among 20 species. Genetic variation ranged from 0.8 to 21.2% among species. Maximum parsimony, maximum likelihood, and Bayesian analysis do not support the recent synonmy of Synansphecia as Pyropteran. Maximum parsimony and maximum likelihood support the recent divergence of Synanthedon pamphyla from Synanthedon culciformis, which are almost identical morphologicaly. Maximum likelihood, parsimony, and Bayesian analysis do not support the inclusion of Melittia cucurbitae in the Sesiinae subfamily. All analysis support Synanthedon included in the Sesiinae subfamily. All analysis also give support for Vitacea and Paranthrene forming the subfamily Paranthrenini. This is the first attempt to resolve relationships within Sesiidae with molecular data. Sesiidae are a divergent order of Lepidoptera in which many relationships should be examined more closely. Future studies should investigate nucleur markers to further support relationships supported by molecular data.