New morphological and molecular data for adult trematodes of Asymphylodorinae from the intestines of two fish species, Leuciscus idus and Tinca tinca from the European part of Russia were obtained. These worms were characterised with conventional morphological technique and by analyses of the 28S rRNA gene sequence variation. Based on molecular data, discovered parasites belong to three known species: Parasymphylodora markewitschi, P. parasquamosa, and Asymphylodora tincae. However, between specimens of each revealed species, except P. parsquamosa, significant morphological differences were detected. Accepting the identity of trematode specimens at molecular level, morphologically different trematodes were recognised as having different morphotypes within both species, including five morphotypes for P. markewitschi and three morphotypes for A. tincae. Results of the present study of European asymphylodorine species morphological and molecular variation considerably differ from that for Far Eastern species, studied earlier. A hypothesis for explanation of this difference was proposed and discussed.