A numerical taxonomic study of ten species of sea hares collected from the Egyptian coast of the Red Sea was conducted based on 135 morphological and anatomical characters. The family Aplysiidae represents two clades; the first clade includes the subfamily Aplysiinae and the second includes the remaining subfamilies namely: Dolabellinae, Dolabriferinae and Notarchinae. For the first clade, the subfamily Aplysiinae forms a monophyletic group, where Aplysia dactylomela forms a sister taxon to A. oculifera and A. coringera, while A. fasciata forms the basal offshoot of the clade. Within the second clade, the subfamily Dolabellinae is grouped as a sister taxon to the subfamily Dolabriferinae and the subfamily Notarchinae is the basal offshoot of the second clade. The genus Phyllaplysia constitutes a sister taxon to the genera Dolabrifera and Petalifera. Further studies are recommended with a comparison between the morphological and the molecular characters.