Protea eximia is a large, upright shrub, 2-5 m tall with a single main trunk and a rather lanky, sparsely branched growth habit. The leaves are greyish green to purplish green and are coated with a whitish bloom that can be rubbed off (glaucous). The leaves are leathery and hairless, narrowly to broadly egg-shaped, 60-100 x 30-65 mm. The base of the leaf, where it attaches to the petiole, is heart-shaped with a deep notch where the petiole is inserted (cordate), and in some plants the two rounded lobes at the base of the leaf are ear-shaped and project quite prominently (auriculate).

The flower heads are large, 100-140 mm long, and up to 120 mm across when fully opened. The outer surfaces of the floral bracts are covered in fine silky hairs (sericeous) and the margins are fringed with hairs (ciliate). The outer series of floral bracts (those lower down on the flower head) are usually greenish or yellowish white or white flushed with pink, with a brown edge. The inner series of floral bracts are long and spoon-shaped, and usually deep pink, although colour varies in wild populations from pink to orange-brown. When the flower head opens, there is a central dark purple ring in the centre.

This is because the tips of the long, narrow flowers massed in the centre of the flower head are covered in purple-black, velvety hairs. At first, no flowers are open and they are all massed together in the centre, so the purple colour is very pronounced. The flowers open from the outside inwards, and as they do so the perianth (with the purple hairs) collapses and separates from the central mass, so the purple ring becomes less pronounced and the colour more diffuse as the flowers open. The collapsed perianths are the thread-like structures that can be seen falling between the floral bracts, and they cause the older flower heads to look rather untidy.

Flowering time is mainly during spring to early summer (August to October) but flower heads are found on the bushes from midwinter until midsummer (June until December).

Protea eximia is easy to tell apart from other proteas by its cordate to auriculate, hairless leaves, spoon-shaped floral bracts and purple-centred flower head. It is most often confused with the hybrids Sylvia and Cardinal, which are hybrids between itself and P. susannae and they have inherited its purple-centred flower head but not its foliage.