In this contribution we present the first record of a member of the family Argyrolagidae (Metatheria) recovered from the India Muerta Formation (late Miocene) exposed near San Miguel de Tucumán, Tucumán Province, Argentina. The specimen is represented by a fragment of right maxilla with M1–4 and is referred here as Microtragulus Ameghino. It clearly differs from other members of the genus that preserve the upper dentition. Nevertheless, the impossibility of comparing this material with species only known by lower dentition, such as Microtragulus catamarcensis (Kraglievich) prevent us from establishing whether this is a new species or not. The comparisons performed allow us to identify characters from the upper dentition differing between Microtragulus and Argyrolagus Ameghino. These characters, in turn, led to the reassignment of a species previously assigned to Microtragulus. The new record reported here, the third known of Microtragulus from northwestern Argentina, broadens the geographic range of the genus, known from the Atlantic coast of Argentina and several localities of the Andean highlands and the foothills of the cordilleran range.