Domestic and wild mammals in Byelorussian Polesye have been found to have 3 species of echinostomatates known as human parasites: Echinochasmus perfoliatus (Ratz, 1908), Echinostoma revolutum (Froelich, 1802) and Isthmiophora (= Euraryphium) melis (Schrank, 1788). Human beings may be infected on ingestion of mollusks, fish, and Amphibia (frogs) invaded with larvae of these helminths. Although, cases of human invasion have not been recorded in Byelarus, there is an infection risk group, this should be borne in mind by medical workers.