It is sedentary in lower and upper montane evergreen forest, including elfin forest, from c.820 m to at least 1,600 m, and was once found at 1,800 m. It is usually found in steep areas or along ridges with exposed corestones, some bamboo and climbing palms. It is less vocal than other members of the genus, and is hence less easily detectable.

Polyplectron inopinatum is currently only known from central Peninsular Malaysia and (very narrowly) adjacent extreme southern Thailand. In Malaysia it is found in the Main Range from the Cameron Highlands south to the Genting Highlands, in the Larut Range to the north-west, and on eastern outlying peaks Gunung Tahan and Gunung Benom. In Thailand, it is known from the peaks of Hala Bala.

Conservation Actions Underway
It occurs in at least three protected areas, Taman Negara (which encompasses Gunung Tahan, and various other peaks where it could occur), Krau Wildlife Reserve (which incorporates one-third of the flanks of Gunung Benom) and the very small Fraser's Hill Wildlife Sanctuary.

Conservation Actions Proposed
Develop a robust monitoring protocol and monitor populations at known sites. Clarify its distribution and population status within its known range, and establish whether it occurs to the north of this range. Conduct surveys to assess its habitat preferences. Consider a captive conservation breeding programme in case the species' conservation status deteriorates.