A REVISION OF THE GENUS ABDERITES AMEGHINO, 1887 (MARSUPIALIA, PAUCITUBERCULATA). In this contribution, a taxonomic review for the genus Abderites Ameghino is presented. A comparative morphological analysis of the teeth, including a review of the dental homology, was performed. The continuous quantitative characters were evaluated by means of a traditional morphometric analysis. As a result, three species were recognized for the Miocene of Argentina and Chile. From the eight species originally described by Ameghino, only A. crispus Ameghino from the Colhuehuapian (early Miocene) of Argentina, and A. meridionalis Ameghino from the “Pinturan” and Santacrucian (late early Miocene) of Argentina, are considered valid species. In addition, this study allowed identification a new species, Abderites aisenense sp. nov., recorded in the Friasian s.s. and Colloncuran (middle Miocene) from Chile and Argentina respectively. A. pristinus (Ameghino) previously recognized as valid species, is considered nomen dubium.