A new species of Labeo (Cuvier, 1817) is defined and described from the Upper Niger River and Upper Senegal (Baoulé) River basins. Although it is diagnosed as a new species, there is some overlap with two other sympatric species, L. coubie and L. senegalensis, in identifying characters. This overlap is sufficient to introduce the alternative possibility that the putative new species is a hybrid. Three separate techniques were used to test the two competing hypotheses: morphological/morphometric analysis, chromosomal/enzymological analysis, and comparative parasitology. These complementary studies were carried out simultaneously but essentially independently, to minimize any scientific bias during the investigation. It was established that the three species can be distinguished by a combination of mouth morphology and meristics (notably gill raker counts). Though all three have the same chromosome number (2N = 50), the new species can be identified allelically by four homozygous loci that are not present in L. coubie and L. senegalensis. This genetic result indicates that the new species is sexually isolated from the other two. Also, calculations of Nei's genetic distance produce an index which is shorter between L. coubie and L. senegalensis than between either of these two and the prospective new species. All three species can be further separated by their specific monogenean gill-parasite complement: L. coubie (five Dogielius spp., seven Dactylogyrus spp.); L. senegalensis (two Dogielius spp., five Dactylogyrus spp.); Labeo roseopunctatus n.sp (1 Dogielius sp., one Dactylogyrus sp.). As a result of these investigations, the idea of hybridism is rejected and a formal taxonomic description of Labeo roseopunctatus n.sp. is included in this paper.