The works of Anastasius of Sinai offer an important window into the lives of Christians living under Muslim rule at the end of the seventh century. Writing after spending several decades traveling the Muslim-conquered Near East, Anastasius produced works that spoke simultaneously to both the theological significance of Muslim rule and to the continued doctrinal debates between Chalcedonians and anti-Chalcedonians. This article focuses on comparing how Anastasius characterizes Muslims and anti-Chalcedonian Christians, particularly in his Viae dux and collections of edifying tales. Although he often discusses Muslims in connection to demons or other evil forces, these references lack any real sense of horror. Moreover, his works have only limited references to Muslims, and he often use their presence as a pretext to discuss doctrinal variation and heresy instead. It is worth noting that modern study of Anastasius’ corpus has been complicated by confusion over authorship because his works also often lack internal historical references that could be used for consistent dating. Moreover, many aspects of his theology relate to post-Chalcedon doctrine, and therefore could easily be attributed to an author of the sixth century. However, given the monk's travels, which took place during the height of the Muslim incursion into the Levant, the Muslims’ absence may not be merely an accidental omission, but may rather represent a conscious choice by Anastasius to create works that echo pre-Islamic writing, in order to create a sense of continuity and a unified Christian world that was, in reality, disrupted by Muslim rule.