A recent definition of Asterorhombus is composed of only two characters: lack of sexual dimorphism; deep clefts in caudal bones (parhypural, hypurals, epurals). The genus currently contains seven nominal species: A. annulatus, A. bleekeri, A. osculus, A. cocosensis, A. fijiensis, A. intermedius, and A. filifer. Herein the genus is redefined, and as a result, A. annulatus, A. bleekeri, and A. osculus are transferred to Engyprosopon; Asterorhombus is reduced to four nominal species, A. cocosensis, A. fijiensis, A. intermedius, and A. filifer. Asterorhombus fijiensis is shown to be a junior synonym of A. cocosensis. Asterorhombus filifer and A. cocosensis are confirmed to have sexual dimorphism in interorbital width. Species of Asterorhombus were found to show two patterns of distribution: A. intermedius and A. cocosensis, Indo-West Pacific–distributed from the Indian Ocean to the western Pacific, not occurring nonmarginally on the Pacific Plate; A. filifer, Indo-Pacific–distributed from the Indian Ocean to nonmarginal localities on the Pacific Plate.