In my fieldwork, I’ve experienced a great number of people who have a sense of being invaded by an entity from the supernatural realm. The study of spirit possession and exorcism is still in its very early stages and is a field that has not been completely analyzed and exploited according to the scientific method. This article will attempt an anthropological, semiotic approach to spirit possessions, by rationally examining the spiritual experiences of people in various cultures, the physiological and psychological changes they undergo during these experiences, and exorcism as a psychospiritual way of restoring and rehabilitating the psychic state of the victims. Possession today is a widespread, culturally universal phenomenon, and should be considered a scientifically verified one.