Arctostaphylos purissima is a shrub reaching at least 1 metre (3.3 ft) in height, and known to exceed 4 metres (13 ft) tall. It varies in shape from low and spreading to tall and erect.
It is coated in long, white bristles and a dense foliage of shiny, hairless green leaves. Each leaf is round to oval in shape and smooth along the edges, and up to 2.5 centimeters long.
The inflorescence is a hanging cluster of spherical to urn-shaped manzanita flowers each about half a centimeter long.
The fruit is a hairless drupe between one half and one centimeter wide.
