Juliomys pictipes, the type species of this sylvan cricetid genus, remains poorly known. In Argentina, country where the type locality is placed, it is only known from the holotype. Here we report the first new Argentinean individuals, after a gap of 80 years; the new specimens -three in total- include one topotype and allow adding two new recording localities for the species. In addition, we refined the geographical location of their type locality and described in detail several morphological traits of this peculiar mouse, producing an emended diagnosis of both the type species and the genus. Molecular data provided in this paper reinforce the identity of J. pictipes and the reference of the southern Brazilian populations of this genus to the type species.