In the introduction to The World of Gregory of Tours, edited by Kathleen Mitchell and Ian Wood, Peter Brown remarked that the scholarship on Gregory of Tours was “something of an academic industry.” Although works on his histories have certainly topped the list, studies on his hagiographical works are not far behind. I will attempt to add capital to this industry by examining an often-overlooked aspect of the bishop of Tours’ hagiographical works: the possible source materials that underlie some of his narrative accounts. This paper examines Gregory’s descriptions of demonic encounters in light of the written source materials he most likely had at his disposal and from which he drew inspiration. Certainly utilizing local folk and oral tradition as well, Gregory frames his narrative accounts within the rich patristic, especially monastic literature in which he was so immersed. I propose that, along with such sources as Sulpicius Severus, John Cassian, Caesarius of Arles, and Paulinus of Nola, Gregory may also have drawn directly from the Latin version of Athanasius’ Life of St. Anthony. Although his demonic-encounter narratives are certainly uniquely his own, I will show that Gregory transmits important aspects of this rich patristic demonological tradition, such as certain animal and fantastical forms, typical colors, and overall narrative characteristics, within his hagiographical works; a tradition which was to become part and parcel of the western medieval demonological industry to follow.