Here I reviewed the Pleistocene caviomorphs collected by Santiago Roth (collection from Catalog No. 5) and housed at the paleontological collection of the Paläontologisches Institut und Museum, Universität Zürich, Zurich (Switzerland). The fossils were found in Pleistocene strata from Buenos Aires and Santa Fé provinces (Argentina) during the late nineteenth century. The material includes craniomandibular remains assigned toLagostomus maximus(Chinchilloidea: Chinchillidae), craniomandibular and postcranial (thoracic and sacral vertebra, left scapula, left femur, and right tibia) bones identified asDolichotissp. (Cavioidea: Caviidae), and a fragmented hemimandible and isolated tooth ofMyocastorsp. (Octodontoidea: Echimyidae). Other rodent specimens from this collection (Ctenomyssp. andCaviasp.) are possibly sub-recent materials.