Although there have been previous studies in social psychology on the association between self-awareness and aggression, none has investigated the relationship in computer-mediated communication (CMC). The present study aims to replicate the findings in the context of CMC, by replacing the traditional mirror manipulation of private self-awareness with a real-time video image of oneself, and by measuring the intention of verbal aggression in abusive user comments on online news articles. As predicted, two experiments (N = 163) found that participants were less likely to agree with abusive comments and intend to write such comments when private self-awareness is induced. The effects of device size, self-monitoring, and social norm were also examined. In addition to extending theories of self-awareness to the context of CMC, the study offers a novel approach to addressing incivility on the Internet.