The shrub has a bushy habit and typically grows to a height of 3 m (9.8 ft) and has angled reddish brown branchlets.

The thin grey green phyllodes are ascending to erect with an oblanceolate shape and a length of 2.5 to 5.5 cm (0.98 to 2.17 in) and a width of 3 to 10 m (9.8 to 32.8 ft) with a fine but distinct midrib and obscure lateral nerves.

The shiny black seeds within the pods have an oblong to elliptic shape and a length of 4 to 5 mm (0.16 to 0.20 in).

It was reclassified as Racosperma chalkeri in 2003 by Leslie Pedley then transferred back to the genus Acacia in 2006.

[3] The specific epithet honours Thomas Michael Chalker who worked as a caretaker at Wombeyan Caves.