Using all data sources available, we collected 2,189 nominal scientific names that have been applied to the fishes from Gabon. Data from the literature and online database indicate that 1,062 valid species of fishes live in Gabonese waters, with 288 of these strictly restricted to freshwaters, 592 strictly restricted to marine environments and 182 species euryhaline species. Among the latter one finds 121 species inhabit in both marine and brackish environments, 16 that occur in both freshwater and brackish environments and 45 found in all salinities. These 1,062 species represent 60 orders and 224 families. An additional 202 species, mostly marine, may be present in Gabon although they have not been yet recorded. Endemic species represent 7% (75) of the 1,062 valid described species for Gabon, within just one of these from marine waters and 74 freshwaters spe­cies (mostly killifish within the genus Aphyosemion – 33 species). Regarding the IUCN status, 135 present (+19 possible) species (12.7%) are considered as endangered (from near threatened to critically endangered), and 135 (+24 possible) (12.7%) species are not evaluated or data deficient. The remaining species are least concern. Continued descriptions of new species from the waters of Gabon demonstrate that the present total most likely underestimates the species level diversity of the fish fauna.