The muzzle and sides of the head are often brightly colored with yellow, orange, or red. The underparts are brownish, orangish, yellowish, or whitish. The short-haired tail, which is white underneath, perhaps is used as an intraspecific signaling device. Myoprocta closely resembles Dasyprocta but is usually much smaller and has a more prominent tail. The incisor teeth are pale orange in color.
Females have four pairs of ventral mammae.
Myoprocta seems restricted to the tropical forests of the Amazon Basin. It is basically diurnal and terrestrial and sometimes lives in holes in riverbanks. Each range contained several areas of high use, with males tending to stay in open forest and females in dense vegetation. Individuals did not dig their own burrows but made leaf nests in hollow logs or old armadillo holes. Social units comprised 1-7 individuals, frequently an adult male and female with juveniles.