The genus Paroppia comprises four species, none of which occur in South America. Here a new species, P. patagonica, is described from adult specimens collected in Nothofagus forests of Northwestern Patagonia. Paroppia patagonica differs from other species in this genus by the shape of the aciculated fusiform sensillus, the size and position of inter-lamellar sigillae, the position of notogastral and genital setae, and the small thick notogastral c2 and exobothridial setae. Classification and description of leg setae and solenidia according to Grandjean is given. An identification key to known species of Paroppia is proposed. Morphological characters shared between Paroppia and Taiwanoppia senegalensis are briefly discussed.