This very symmetrical plant supports a crown of shiny, dark green leaves on a thick shaggy trunk that is typically about 20 cm (8 in.) in diameter, sometimes wider. The trunk is very low to subterranean in young plants, but lengthens above ground with age. It can grow into very old specimens with 6–7 m (over 20 feet) of trunk; however, the plant is very slow-growing and requires about 50–100 years to achieve this height. Trunks can branch multiple times, thus producing multiple heads of leaves.
The leaves are a deep semiglossy green and about 50–150 cm (18-45 in.) long when the plants are of a reproductive age. They grow out into a feather-like rosette to 1 m (3 feet) in diameter. The crowded, stiff, narrow leaflets are 8–18 cm (~7 in.) long and have strongly recurved or revolute edges. The basal leaflets become more like spines. The petiole or stems of the Sago Cycad are 6–10 cm (2.5-4 in.) long and have small protective barbs that must be avoided.
Propagation of Cycas revoluta is either by seed or by removal of basal offsets. As with other cycads, it is dioecious, with the males bearing cones and the females bearing groups of megasporophylls. Pollination can be done naturally by insects or artificially.
Of all the cycads, the Sago Palm is the most popular in horticulture. It is seen in almost all botanical gardens, in both temperate and tropical locations. In many areas of the world, it is heavily promoted commercially as a landscape plant. It is also quite popular as a bonsai plant. First described in the late 1700s, it is native to various areas of southern Japan and is thus tolerant of mild to somewhat cold temperatures, provided the ground is dry. Frond damage can occur at temperatures below −5 °C. It does however require hot summers with mean temperatures of 30 to 35 °C (86 to 95 F) for successful growth, making outdoor growing impossible in colder places such as northern Europe, even where winter temperatures are not too cold. One disadvantage of its domestic use is that it is poisonous to animals and humans.
All parts of the plant are toxic, however, the seeds contain the highest level of the toxin cycasin. Cycasin causes gastrointestinal irritation, and in high enough doses, leads to liver failure. Other toxins include Beta-methylamino L-alanine, a neurotoxic amino acid; and an unidentified toxin which has been observed to cause hindlimb paralysis in cattle.