Three rheophilic species of the western Palaearctic Barbus with adjacent geographic distributions are recognised in the Danube River basin, each diagnosed by a set of unique mitochondrial DNA alleles. Barbus petenyi Heckel, 1852 from the Eastern and Southern Carpathians and from the Stara Planina Mts is redescribed and a neotype is designated. Barbus carpathicus, new species, is distributed in the Western and Eastern Carpathians. Barbus balcanicus, new species, occurs in the Dinaric and Western Stara Planina Mts. The three species are morphologically similar to each other but B. balcanicus can be distinguished by subtle differences in the snout shape and body and fin colour pattern. As evident from genetic data the name B. cyclolepis waleckii Rolik, 1970 was proposed for the hybrids between B. barbus and B. carpathicus and cannot be used as valid.