Mature bark is reddish-brown, scaly, thick and furrowed.
Needles are yellowish green on their upper surface and whitish with 2 thin lines of stomata on their lower surface. They are short, flat and blunt, irregularly spaced and of unequal length: needles on the same twig can be 0.5-2 cm long. They are arranged spirally around twigs, but are twisted at the base so they appear to extend horizontally in two tiers.
Pollen cones are small and numerous.
Seed cones are also numerous and approximately 2 cm long and oblong. They are purplish-green when young and become light brown when mature.
Western hemlock are distinguished by their unequal needle length and the feathery, flat appearance of their branches. They have a noticeably drooping leader.