The Capricorn Leaf-eared Mouse lives on the eastern slopes of the Andes, from southern Bolivia to northern Argentina. It has been recorded in high-elevation brushland.
It is relatively large and short-furred. Compared with the similar P. xanthopygus, it has a thicker tail and often a buff-colored band across the chest.
It lives in brushy habitats of southern Bolivia and northern Argentina and has been collected among scattered shrubs and prickly pear cactus at about 2,600 m.
At Tilcara in northern Argentina, it lives around brushy hedgerows and stonewalls.
At Alfarcito, east of Tilcara, it occurs with Phyllotis xanthopygus in a mixture of brushy and open habitats.
Reported head-and-body length is 102–140 mm, with a mean of 118 mm.
An extinction-risk assessment has not been added yet.