Mountain Thornbills are strictly rainforest birds - restricted to the mountain rainforests of NE Queensland from near Cooktown to just west of Townsville. They are not easy birds to observe because they forage in the mid-levels of the forest, up to 20 metres or so from the ground. Many people do compare them to Brown Thornbills in habits and appearance - their most obvious field mark is the bright, almost white, eye.

Mountain Thornbills build a large suspended, domed shaped nest which is covered in green moss, well camouflaged in the rainforest. They do appear to breed as simple pairs but whether there are extra helpers at the nest is not known. Certainly, in the non-breeding season they do occur in parties of up to 10 birds which are more than likely to be large family groups, the result of more than one successful nesting.