Coprosma linariifolia is an erect, tall, openly-branched shrub or small tree growing to 8 m. It usually has a single trunk with rather smooth to rough fawn-grey bark. The inner bark is bright yellow to deep orange-yellow.

The narrowly elliptical leaves which are up to 33 mm long and up to 5 mm wide are often slightly crescent-shaped, with almost parallel margins. The flowers are unisexual. The oblong fruit (6 mm long) are solitary, white, often flecked with blue or blue-black, sometimes uniformly black. Coprosma linariifolia is found growing from Mt Tongariro in the North Island to Waitutu, the southern limit in the South Island. It is absent from most of Westland, and not very common in Fiordland. In Taranaki, it found at Taihape and Mangaweka. Its habitat is lowland to montane forest, scrub, and sometimes shrubland. Its altitude range is 25–1065 m.