Sinha, A., Datta, A., Madhusudan, M. D., & Mishra, C. (2005. Macaca munzala: A new species from western Arunachal Pradesh, northeastern India. International Journal of Primatology, 26, 977–989) discovered Arunachal macaques (Macaca munzala), a species new to science, in the eastern Himalaya of Arunachal Pradesh in northeastern India. They depicted the holotype and paratypes of the species in photographs, and a specimen of the species had been unavailable for preservation and examination. In March 2005, we obtained an entire specimen of an adult male Macaca munzala, which we propose as a voucher specimen for the species. We provide detailed morphological and anatomical measurements of the specimen and examine its affinities with other macaques. Macaca munzala appears to be unique among macaques in craniodental size and structure, baculum, and aspects of caudal structure, while exhibiting affinities with the other members of the sinica-group to which it belongs. We summarize our insights on the origins and phylogeny of Macaca munzala. Finally, we review the current conservation status of the macaques, which are threatened by extensive hunting in the only 2 districts of Arunachal Pradesh where they are documented to occur.