Humboldt's night monkey occurs in Venezuela and northern Brazil. It uses humid forests, including seasonally flooded forest, and eats fruits, nectar, and other foods.
The adult head-and-body length listed by ICMBio is 341 mm for females and 346 mm for males. Tail length is 373 mm in females and 354 mm in males, longer than the head and body in both.
It occurs in humid lowland, flooded, and montane forests, and is also recorded in altered forest, including selectively logged areas. Its diet includes fruits, nectar, flowers, leaves, and small prey such as insects.
An extinction-risk assessment has not been added yet.