It is found in the Indian subcontinent and Southeast Asia, ranging across Bangladesh, Bhutan, Brunei, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, the Philippines, Singapore, Thailand and Vietnam.

Locally, the great slaty woodpecker prefers sprawling stands of dipterocarp and teak trees.

Occasionally, at first glance, the great slaty woodpecker is mistaken for a hornbill but, obviously, such a resemblance is slight at best.

In more antagonistic situations, sharp taw-whit or dew-it calls are uttered while the birds swing their heads back and forth.

Groups often forage on shared feeding sites in the form of nests of social insects as ants, termites, wood-boring beetles and stingless bees.

The groups will travel considerable distance to access these trees and, as such, the home ranges of the species are quite large.

The great slaty woodpecker usually works a tree upwards and, though capable of swifter movements, has been described while foraging as if moving in "slow motion".

It forages by gleaning, probing, pecking, prising off bark and hammering with powerful and loud blows to excavate the wood.

Gleaning is the most important foraging method for the species, with the long neck and bill allowing it to reach out over a considerable distance into the cracks and crevices of trees.

[2] Like all woodpeckers, breeding pairs roost in separate tree holes but regularly vocalized to stay in contact.

Displays include head-swinging, where the appears to lag behind the body in swinging movements, whinnying calls and widen their wings and tail considerably.