The yellow-crowned brush-tailed rat, Isothrix bistriata, is a South American brush-tailed rat species from the family Echimyidae. It is found in Bolivia, Brazil, Colombia, Ecuador and Peru and Venezuela. They are nocturnal and arboreal animals found in lowland evergreen rainforest, probably restricted to igapó and várzea habitats. Sometimes they can be seen at the entrances of their dens, in tree holes (specially hollow palms) on the borders of rivers.