Gyrodactylus parvae n. sp. is described from the fins and body surface of the topmouth gudgeon Pseudorasbora parva (Cyprinidae) in cold-water streams of the Qinling Mountains, central China. Morphology and rDNA sequence data identify the parasite as a new member of the wageneri species-group. Members of this lineage have successfully invaded a variety of freshwater fish lineages throughout the northern hemisphere, with this known range now extending to cyprinids in mountain streams of central China. Gyrodactylus parvae n. sp. is compared to other similar members of the group. The present study is, to our knowledge, the first report of a viviparous monogene from P. parva within its natural range and brings the total number of species of Gyrodactylus known from freshwater fishes of mainland China to 47.