Red-osier dogwood grows as a medium to tall upright shrub. Stems rise poker-straight from the crown reaching as little as a meter high in the northern interior to 8 m or more on the southern coast. Typical stems are smooth, rounded and wine red, though large coastal forms are often green or even grey. Rooted side shoots often develop and stems arch and root at the ground forming dense thickets. The branches are arranged in pairs opposite each other, each pair positioned at right angles to the pair above and below.
Twigs often curve inward from the midpoint, tracing the outline of a wine goblet.
Bright red naked winter branches provide an eye-catching display against the gleaming winter snow. The sharply pointed leaves are oval to ellipse shaped, reaching about 10 cm long. The upper surface is usually medium to dark green but the underside is distinctly grey-green. In the fall, leaves usually turn maroon before falling. The veins arch gracefully to the leaf edge.