It has a black body (approximately 20 cm (7.9 in) long) and white head.

The range of the white-headed woodpecker stretches in the mountains from British Columbia through southern California.

mtDNA cytochrome b and ATP synthase subunit 6 sequence data confirms this arrangement and also suggests that the Mount Pinos birds are closer to L. a. gravirostris (Alexander & Burns, 2006).

Apparently, the larger bill of the southern subspecies is an adaptation for being better able to feed on the large, spiny cones of Coulter pines (Pinus coulteri).

Some taxonomic authorities, including the American Ornithological Society, place this species in the genus Dryobates.