The affliction of demonic possession and its treatment through the rite of exorcism took on new significance in the peak period of witch trials (c. 1430–c. 1750). The most dramatic aspect of this development was the performance of exorcism on persons believed to have become possessed because of another’s evil acts, leading to witch trials. This article profiles the distinctive features of possession and exorcism in this historical period, and then considers the problem identified by Lederer: in what ways did the beliefs about possession, exorcism, and witchcraft intersect? It begins by providing an overview of the characteristic developments of the period: the rise of the exorcist; the significance of the role model of the medieval holy woman; and the emergence of the demoniac as both witchcraft victim and prophetess (but also as possible witch). To analyse these trends, the article explores just one link between the three phenomena: the primacy given to vigilance in guarding against devil-worship in cases of possession, exorcism, and witchcraft.