We report on the current status and threats to Lagothrix flavicauda and other primates that inhabit montane forest of the Región Huánuco; an area that has been little explored with regard to its primate fauna and other mammals. During 618 km of transect walks in June-July 2014 and September-October 2014, we encountered 47 groups of five primate species, the most common being Alouatta seniculus (15 groups) and Lagothrix flavicauda (13 groups). We also observed four groups of Aotus sp. in the Miraflores census site. Lagothrix flavicauda was seen only in the microbasin of the Río Chontayacu, and Ateles chamek in the upper Río Huallaga. The primates were living in patches of primary and remnant forest surrounded by farmland and pasture except in Chontayacu, where the forest is still dense and extensive. Of the three species with complete counts, group sizes were largest for L. flavicauda (mean 13.6 ±7.8, n = 5) and smallest for A. seniculus (mean 5 ±3.5, n = 11). Population densities were highest for L. flavicauda (20.8 ind./km2) and lowest for Sapajus macrocephalus (2.7 ind./km2). Deforestation for agriculture and cattle ranching and hunting are the major threats to the survival of these primates. Sapajus macrocephalus and Cebus yuracus were the most affected by these threats, particularly in the Río Chinchao microbasin,.