It is a tree or shrub with furrowed bark, woolly-hairy branchlets, narrowly linear leaves and cream-coloured to greenish-yellow flowers.

The leaves are straight to curved, and densely covered with woolly hairs pressed against the surface at first, later glabrous.

Up to 200 flowers are arranged on a floral rachis mostly 60–200 mm (2.4–7.9 in) long, usually with cream-coloured or white woolly hairs pressed against the surface.

[3][4][5] Hakea macrocarpa was first formally described by the botanist Robert Brown in Supplementum primum Prodromi florae Novae Hollandiae.

[8] Flat-leaved hakea grows in red sandy soils on coastal sand dunes, sand dunes, rocky ridges and sandplains in the Central Kimberley, Dampierland, Great Sandy Desert, Northern Kimberley, Ord Victoria Plain, Pilbara, Tanami bioregions of Western Australia, the central Northern Territory and western Queensland.