Cupressus macrocarpa is a medium-sized coniferous evergreen tree, which often becomes irregular and flat-topped as a result of the strong winds that are typical of its native area. It grows to heights of up to 40 mt. in perfect growing conditions, and its trunk diameter can reach 2.5 mt.. The foliage grows in dense sprays which are bright green in color and release a deep lemony aroma when crushed. The leaves are scale-like, 2–5 mm long, and produced on rounded (not flattened) shoots; seedlings up to a year old have needle-like leaves 4–8 mm long.
The seed cones are globose to oblong, 20–40 mm long, with 6–14 scales, green at first, maturing brown about 20–24 months after pollination. The pollen cones are 3–5 mm long, and release their pollen in late winter or early spring.