Paragonimus is a genus of flatworms (platyhelminths). Some tens of species have been described, but they are difficult to distinguish, so it is not clear how many of the named species may be synonyms. Several of the species are known as lung flukes. In humans some of the species occur as zoonoses; the term for the condition is paragonimiasis. The first intermediate hosts of Paragonimus include at least 54 species of freshwater snails from superfamilies Cerithioidea and Rissooidea.