It is a shrub or small tree with aromatic, pinnate leaves and groups of between two and six bright pink flowers in the leaf axils.

Boronia thujona is a glabrous shrub or small tree that grows to a height of 1–4 m (3–10 ft) with two grooves between the leaf bases on the smaller stems.

[2][3] Boronia thujona was first formally described in 1922 by Arthur de Ramon Penfold and Marcus Baldwin Welch and the description was published in Journal and proceedings of the Royal Society of New South Wales.

[4][5] The specific epithet (thujona) refers to the ketone, thujone that Penfold, a chemist, and Welch, an economic botanist, extracted from this plant.

[2] The bronzy boronia grows in damp, shady forest in the Sydney region and south to the Budawang Range.