The taxonomic status of its 59 nominal species of the genus Bothus (Pleuronectiformes: Bothidae) has been revised, based on a morphological study of 320 type and non-type specimens. Of the 59 nominal species examined in the study, 18 have found to be valid and are re-described. The genus Bothus (pro parte) is considered natural on the basis of two characters previously identified by Hoshino and Amaoka (2006): a ventral expansion of the haemapophyses of the precaudal vertebrae and the bony expansion of the haemal spine of the first caudal vertebrae. These characters were observed in all accepted species of Bothus, excluding B. swio. The morphology of B. swio overlaps with other bothid genera, but its generic placement was not analysed. Engyrprosopon and Crossorhombus are hypothesized as outgroups of Bothus based on the character state identified by Hoshino and Amaoka (2006), an anterior extension of the sciatic part of the urohyal past the main part of the urohyal. A phylogenetic analysis of the Bothidae is needed to substantiate this hypothesis of relationship, to validate the monophyly of Bothus and to resolve the generic position of B. swio. The geographic distribution of each species is mapped and an up-to-date species identification key has been created. The 18 valid species are as follows, with their synonym species in parenthesis: Bothus assimilis, Bothus constellatus, Bothus ellipticus, Bothus guibei (Rhombus heterophthalmus), Bothus leopardinus, Bothus lunatus, Bothus maculiferus, Bothus mancus (Pleuronectes barfi, Rhombus macropterus), Bothus mellissi, Bothus myriaster (Citharicthys aureus), Bothus ocellatus (Platophrys nebularis, Rhomboidichtys spinosus, Rhombus bahianus), Bothus pantherinus, Bothus podas (Bothus rumolo, Bothus tappa, Rhombus gesneri), Bothus robinsi, Bothus swio, Bothus thompsoni, Bothus tricirrhitus, and Bothus ypsigrammus.