[4] When in 1758 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the tenth edition, he placed the grey peacock-pheasant with the Indian peafowl in the genus Pavo.

[8] Although several subspecies have been described, none are currently recognised in the list of world birds maintained by Frank Gill, Pamela Rasmussen and David Donsker on behalf of the International Ornithological Committee (IOC).

Though they are quite similar on the molecular level, the distance and interspersed populations of their closest relatives argue against a much more recently shared common ancestry between them versus the other two "northern" peacock-pheasants.

All that can be reasonably assumed is that the grey peacock-pheasant evolved on mainland Southeast Asia, probably during the Late Pliocene to Early Pleistocene 3.6-1 million years ago.

[12] It is a large pheasant, up to 76 cm long and greyish brown with finely spotted green eyespots, an elongated bushy crest, bare pink or yellow facial skin, white throat, and grey iris, bill and legs.

The grey peacock-pheasant is distributed in lowland and hill forests of Bangladesh, Northeast India and Southeast Asia, but excluding most of Indochina as well as the entire Malayan Peninsula.