Eight species of fishes from rivers of Northern Portugal were examined for cestodes but only one, Barbus barbus bocagei (Steindachner), was infected: river Este (4 of 12 infected, 1,1,4 adult and 37 juvenile cestodes found respectively), Lima (1 of 8 infected, 1 juvenile cestode), Paiva (1 of 5 infected, 57 juvenile cestodes) and Sousa (1 of 13 infected, 1 adult cestode). The cestodes were Caryophyllidea. The fan-shaped scolex had very shallow incisions, with the scolex separated from the hindbody by a neck. The first vitelline follicles started a considerable distance anterior to the testes, with some vitelline follicles along the lateral margins of the cirrus sac, uterine coils and H-shaped ovary. The uterine coils extended forward to the posterior half of the cirrus sac. Transverse transmission electron microscope sections showed cortical vitelline follicles and medullary testes validating Lytocestidae. These features identify Khawia baltica Szidat, 1941, described from tench Tinca tinca (L.) in East Prussia and subsequently reported from barbel B. barbus and T. tinea in Russia, This is a new host and first record from Portugal and western Europe, thus extending the known range of distribution of K. baltica.