This article presents a review of zombiism and our personal investigations on the hitherto little-known spirit zombi. The Haitian zombi is of African origin. Numerous references to zombis or zombi-like entities are found in Equatorial and Central Africa and in the Caribbean. There are two types of zombis, the zombi of the body, or living dead, and the zombi of the soul. Both are closely related to the Haitian concept of a dual soul, which is also of African origin. Properties of the spirit zombi are described. Zombi stories or sightings may be explained by the observation of vagrant or exploited mentally ill. The various "zombi powders" so far studied seem to belong to the domain of sympathetic magic, and their pharmacological effectiveness remains to be proved.