The recently described Arunachal macaque, Macaca munzala, has to date been reported only from western Arunachal Pradesh, Eastern Himalaya. Our surveys have recorded a total of 35 troops and 569 individuals, probably a conservative estimate, for the macaque population in the Tawang and West Kameng districts of the state. The species appears to be tolerant to anthropo- genic habitat change, but is vulnerable to hunting and retaliatory killing in response to crop damage. Data from one part of the area surveyed, however, indicate that the species can attain remarkably high population densities in the absence of hunting. Macaca munzala will need to be protected in human-modified landscapes, and the issues of crop damage and retaliatory persecution must be addressed urgently.