External morphological and osteological characters are examined in more than 280 specimens of the whitefin gudgeon from most basins within the range of this species. For the first time, cephalic sensory canals and vertebrae are compared in samples from numerous localities. Variations are revealed in most morphometric, osteological and sensory canal characters. It is shown that the geographic variation in many characters has a mosaic-like pattern, rather than an unidirectional one. Fairly stable are combinations of certain characters in samples within each from river basins. This serves as a basis for considering different geographic groups as subspecies and description of a new one, Romanogobio albipinnatus tanaiticus, from the Don River basin.