Plecturocebus vieirai occurs in the Brazilian states of Mato Grosso and Pará. Its original description reports a pale gray-brown coat and white facial markings, while the ICMBio species sheet describes humid forest and streamside sites with buriti palms.
White fur on the forehead, sideburns, and beard forms a continuous frame around the blackish face. The body is pale gray-brown, with orange on the belly and inner limbs.
The ICMBio species sheet reports it in humid forest and along small streams where buriti palms grow. The sheet says it is not known whether the species tolerates disturbed habitat.
An extinction-risk assessment has not been added yet.