A phylogenetic analysis of 13 species of the genus Anisota was carried out using morphological data from mature larvae. Based on quantitative traits, length, and structure of scoli, 18 characters from 3 thoracic and 4 abdominal segments were characterized and coded. The phylogenetic analysis using the larval scoli yielded results in conjunction with previously proposed taxonomic relationships. For instance, the eastern North American species A. consularis, A. fuscosa, and A. manitobensis were found to share a close relationship. Similarly, A. discolor, A. virginiensis, and A. pellucida, three other eastern North American species, were found to be most closely related. However, discrepencies between expected and actual results were also observed: A. stigma and A. leucostygma fell out as sister species to all other Anisota species. This disassociation of the two species from their nearest relatives is believed to be due to the longer branched scoli found on both species and the designated outgroup, Citheronia regalis.