Cephalocereus senilis is a tall, columnar species with clusters of stems that may grow to 5–15 m tall; the individual stems are usually unbranched, being unable to withstand the weight of side branches adequately.

The coat is a particularly striking silvery white on the young cactus; as the plant ages the stem begins to lose its covering.

However, the hairs are only the radial spines of the cactus; they conceal formidable sharp yellow central spines that belie the inoffensive appearance of the hairy covering.

Cephalocereus senilis is a very popular cactus in cultivation, grown for its woolly appearance.

It prefers a very well-drained soil mix (more so than many other cacti), and much bright sunlight, which encourages growth of the hair.