We present the first cladistic analysis of Argia species, focusing on those occurring in North America north of Mexico. Our analysis is based on mitochondrial 16S rDNA and morphological characters of both sexes of adults and immatures. We reexamine classical work on Argia taxonomy and phylogeny. Our results agree considerably with previous hypotheses based morphology in an absence of phylogenetic analysis, and thus our work represents and independent test of these previous hypotheses. Argia is recovered as monophyletic. The clade composed of A. funcki plus A. lugens is basal among the species studied here. The species A. fumipennis, including the three subspecies, appears to be a paraphyletic assemblage, and thus may warrant being considered separate species as originally described. The feasibility of producing a thorough phylogenetic analysis of the entire genus using multiple sources of data is discussed.