We studied morphological differentiation of the eastern spadefoot toad (Pelobates syriacus) in fourteen population samples from Serbia, Macedonia, Bulgaria, and Turkey, Nineteen morphometric and six qualitative characters were analyzed using univariate and multivariate statistical analyses. On the basis of morphology. the samples can be divided into three groups: Serbian, Bulgarian + Macedonian, and Turkish (Asia Minor). Populations from Turkish Thrace (Edirne) appeared to be closer to the Bulgaria + Macedonia group than to populations from Asia Minor. As a result of our work, the range of P.s. balcanicus has been redefined and a separate taxon for Serbian populations has been suggested.