The family Chilinidae in Argentina has been thought to include 19 species. We provide new information on the shells, radulae, reproductive and nervous systems, and the molecular genetics of the chilinid species from the Cuyo Malacological Province (as defined by Núñez, V., Gutiérrez Gregoric, D.E. & Rumi, A. (2010) Freshwater gastropod provinces from Argentina. Malacologia 53, 47–60), along with the description of two new species. Chilina sanjuanina n. sp. is characterized by a small shell with a conical and low spire and with one columellar tooth, a radula with an asymmetric central bicuspid tooth, and a penis sheath with an inner sculpture with regular conical pustules over the entire surface. Chilina cuyana n. sp. has a small shell with a low spire and two columellar teeth and a radula with an asymmetric tricuspid central tooth with serrated edges. The other two species in this province, Chilina mendozana and Chilina parchappii, are redescribed. Mitochondrial gene cytochrome c oxidase subunit I sequences between C. sanjuanina and C. mendozana differ by 4%.