We present an updated checklist of the marine fish from of Oaxaca, southern Pacific coast, Mexico, which is composed of 487 species included in two classes, 36 orders, 108 families, and 284 genera. Three species are new records for Mexican Pacific sout coast: Echinorhinus cookei, Heterodontus mexicanus and Masturus lanceolatus. Records of Urotrygon cimar and Rhinobatus prahli confirm presence of these species in Mexico. Families with the higher specific richness were: Sciaenidae (30), Carangidae (28) and Haemulidae (24). Biogeographically, fish species showed a higher affinity to Panamanian province (78.4%), followed by Sinuscalifornian (67.8%), Galapagos (28.5%), San Diego (35.7%) and Peru-Chilean (11.7%) provinces.