Recent collecting efforts in the upper Malagarazi Basin (2013 2021) allowed for an integrative study based on qualitative (colour), morphological and barcoding (mtDNA, COI) data of specimens similar to Enteromius sP. ascutelatus ; a previously identifi ed, potentially, new species. The present study confi rms its identifi cation as a new species for science, which is here formally described as Enteromius nzigidaherai sp. nov. This new species belongs to the group of Enteromius species: (i) for which the last unbranched ray of the dorsal fin is flexible and devoid of serrations along its posterior edge; and (ii) which have a horizontal series of black spots at the midlateral level of the sides. Three congeneric species known from the Congo Basin sensu lato, including two also found in the upper Malagarazi Basin, are most similar to it. However, E. nzigidaherai sp. nov. is distinguished from the two sympatric species, i.e. E. quadrilineatus and E. lineomaculatus, by two morphometrics. Further, it is also distinguished from E. urostigma, known from the upper Congo Basin only, but by a single morphometric only. A barcoding (mtDNA, COI) study revealed that the specimens of E. nzigidaherai sp. nov. form a well-supported, separate, lineage, with a K2P genetic distance of more than 10% with both, E. quadrilineatus and E. lineomaculatus identifi ed specimens from the upper Malagarazi Basin. The new species was found to be endemic to the upper reaches of two left bank affluents of the upper Malagarazi. However, both affluents are threatened by human activities such as: (i) the use of destructive fishing techniques; (ii) overfishing; (iii) deforestation of their riverbanks, resulting in important sediment runoff; (iv) dam building for agricultural irrigation purposes; and (v) the use of agriculture chemicals. Thus, it is hoped that the present description draws renewed attention to the importance of aquatic protection in the region by highlighting (i) the need for the effective establishment of the Malagarazi Natural Reserve, and (ii) concern for its optimal delimitation as to effi ciently protect the entire ichthyofauna of the upper Malagarazi, without excluding the fish species confined to its affluent rivers.