Morphological differentiation among Barbus peloponnesius, B. meridionalis petenyi and B. meridionalis meridionalis has been investigated using multivariate morphometric analysis. B. peloponnesius and B. m. petenyi form a group distinct from the B. m. meridionalis. These findings support the Karaman’s classification (1971) of B. peloponnesius as a distinct species and also indicate that B. peloponnesius and B. m. petenyi probably constitute one species. Furthermore, differences among the B. peloponnesius populations indicate the existence of at least two subspecies in Greece.