This article examines how people’s beliefs about deception in text-based media (i.e., email, instant messenger) and face-to-face communication are distorted by two biases: (a) a self-other asymmetry, whereby people believe themselves to be more honest than their peers across communication contexts; and (b) a media intensification effect, whereby the perceived gap between one’s own and others’ deceptiveness is increased in text-based media, whose affordances (e.g., reduced nonverbal cues) are believed to facilitate deception. We argue that these biases stem from a desire for self-enhancement, or for seeing oneself as good, moral, capable, and impervious to negative media influence. Support for these propositions emerged across a college student sample (Study 1) and a national sample of U.S. adults (Study 2). The results offer a theoretical framework for the distortions in people’s beliefs about mediated deception, and have important practical implications.