Maritrema neomi n. sp. is described based on specimens found in the intestine of the Mediterranean water shrew (Neomys anomalus) from the Ukrainian part of the Carpathian Mountains. The most important diagnostic features of M. neomi are the body size, sucker ratio, shape and length of the cirrus sac, the cirrus sac/body length ratio, and the topography of the intestinal ceca. Maritrema neomi differs from Maritrema carpathica in the length and shape of body, size of eggs and vitelline follicles, and length of uterus; from Maritrema feliui, in length of cirrus sac, the cirrus sac/body length ratio, and length of intestinal ceca; from Maritrema pyrenaica, in the suckers ratio, shape of body, and size of some internal organs; and from metacercariae of Maritrema galloprovinciale, by much smaller size of body and internal organs, size of vitelline follicles, and topography of the vitellarium. The life cycle of M. neomi involves as intermediate hosts prosobranch snails (Terrestribythinella) and gammarid crustaceans (Gammarus (Rivulogammarus) balcanicus).