The fur is soft and thick but not long. The upper parts are grayish brown, the underparts white or cream, and the ears and feet dark brown. The basal portion of the tail is blackish brown, and the distal half to two-thirds is white. The body is stocky, the face elongate, and the tail much longer than the head and body. Paruromys is characterized by an elongate cranium with very wide zygomatic plates, a low braincase, small bullae, short incisive foramina, large and extremely ophisthodont upper incisor teeth, and molars with simple cusp patterns.
Females have three pairs of mammae.
This giant rat is common in forests from coastal lowlands to the highest mountains. It is easily trapped on the ground, on top of fallen tree trunks, or in tangles of woody vines and crowns of short trees. Nests are found on the ground between or inside rotting tree trunks, under boulders, in the interstices of strangler fig roots, and in underground burrows. The diet consists exclusively of fruits. Paruromys is a favorite food of the mountain people of central Sulawesi.