The Sigmodontinae have radiated to encompass all the terrestrial environments and a wide altitudinal gradient through its large geographic distribution. In Northwestern Argentina (NWA) this group constitutes approximately 30% of the mammals of the region. Several works in the last years have contributed to the knowledge of the geographic distribution of the sigmodontine rodents in NWA. Notwithstanding, many of the species are known only by old and scarce records, most of them heavily biased towards more accessible areas. From surveys conducted in the last three years in the area, which include captures and collections of pellets samples of strigiform birds, in this work we report novel distribution records for the species in this group. We contribute with new record for ten species and eight localities. The new records include the addition of Abrothrix illutea and Oxymycterus wayku for Salta province and Andalgalomys cf. A. olrogi for La Rioja province, the first mentions of Calomys lepidus and Phyllotis tucumanus in high altitudinal grasslands located in Monte de Sierras y Bolsones and Akodon boliviensis in the Puna of Argentina, and several distributional records for Abrothrix andina, Neotomys ebriosus, P. anitae, and Reithrodon auritus, four species not well documented in the study area. Finally, we discussed some methodological and taxonomic aspects, and the relevance of each one of the obtained records.