Depending on species, brocket deer are small to medium-sized with stout bodies and large ears. The head-and-body length is , the shoulder height is , and the typical weight , though exceptionally large "M. americana" specimens have weighed as much as . When present, the antlers are small, simple spikes. The pelage varies from reddish to brown to gray. Very roughly, the species can be divided into four groups based on size, color, and habitat (but not necessarily matching their phylogeny):