Ichthyological investigations were conducted on the Black Volta River, a tributary of the Volta River, as part of a broader inventory of fish fauna in Ivorian freshwater ecosystems. Sampling, carried out between 2022 and 2023, employed a combination of techniques including gill nets, longlines, and fish traps, and was complemented by the analysis of artisanal fishing catches. A total of 63 species, belonging to 22 genera and 17 families, were identified. Species richness varied among sites, with 45 species recorded at Vonkoro, 31 at Machinté, 26 at Tchomi, and 21 at Tatama, with eight species common to all four sites. The most dominant families were Mormyridae (26%), Mochokidae (16%), Alestidae (8%), Cichlidae (8%), Claroteidae (7%), and Cyprinidae (6%). The Shannon diversity index ranged from 2.3 (Tatama) to 3.2 (Vonkoro), indicating a relatively high level of biodiversity. Evenness values ranged from 0.74 to 0.85, reflecting a balanced species distribution. According to the International Union for Conservation of Nature (IUCN), 86% of the recorded species were classified as «Least Concern». These findings provide a valuable scientific baseline for the sustainable management and conservation of the ichthyofauna in the Black Volta River basin.