AbstractElongation factor-1 alpha (EF-1α) is already widely used and shows even more promise for phylogenetic studies of Hexapoda. However, paralogous copies and the presence of introns pose problems. We survey exon-intron structure, presence of paralogous copies and the number and extent of sequenced regions in all hexapod orders. We assess the phylogenetic utility of the exon-intron structure of EF-1α, which is unexpectedly dynamic with widespread losses and several independent instances of intron gain. Paralogous copies of EF-1α are present in Hemiptera, Thysanoptera, Neuropterida, Coleoptera, Hymenoptera and Diptera. With the presented information about exon-intron structure and paralogous copies, researchers will be able to realise the full phylogenetic potential of EF-1α, including exon-intron structure as this can provide additional characters and help to define clades and paralogous copies. We recommend a suitable focus region of 500 bp for future studies of EF-1α in Hexapoda.