Protea roupelliae subsp. hamiltonii grows up to 0.3 m tall, sprawling to form a low mat of about 1 m in diameter in its natural habitat, although there is an old specimen in the Protea Garden at Kirstenbosch National Botanical Garden, that is about 1 m tall and 2.5 m wide

The leaves are linear-lanceolate to obovate, 80–170 mm long and 15–50 mm wide, with rounded to pointed tips, sclerophyllous (hard and leathery), emerald-green. They can be either hairless or with shaggy to silky hairs.

Proteas in general, produce flowerheads or inflorescences made of many small flowers massed together within a cup of usually coloured floral bracts. The male and female elements are carried in the same flower; the female consists of a stigma and pollen presenter, style and ovary; and the male consists of stamens and anthers. The dwarf silver sugarbush has an oblong-obconic to goblet-shaped flowerhead of 80–120 mm long and 80–100 mm in diameter. The outer series of bracts are always shorter than the inner series of bracts, which are 50–100 mm long and 6–10 mm wide. The inner bracts are pink or ruddy to brown, spoon- or tongue-shaped, with silky hairs, with the tip pointed in the floral bracts cup and can often be widely spaced.

This species flowers in late summer to autumn (February to April). When the flowerheads open, the involucral bracts expose the many individual florets that are green at the bottom and pink toward the tips.

It is similar to Protea roupelliae subsp. roupelliae, the silver sugarbush. These two subspecies differ primarily in their growth form, with the latter forming a small upright tree of about 4–8 m high.