Although there is a body of literature that addresses victimization of adolescents based on their membership in stigmatized groups, there is little that focuses on this type of aggression delivered digitally. Furthermore, the extant literature typically focuses on the targets of such aggression, but scant attention has been paid to the aggressors. To address this gap, the current study investigated characteristics of perpetrators of bias-based cyberaggression in a sample of 554 self-reported cyber-aggressors among 1695 12- to15-year-old adolescents in northwestern Mexico. Approximately one-fourth of these cyber-aggressors engaged in bias-based cyberaggression. Demographic characteristics were investigated in an attempt to describe those most at risk for perpetration of bias-based aggression. In addition, the influence of moral disengagement was examined in this unique sample. Results showed that cyber-aggressors who were male and younger were disproportionately represented among those whose cyberaggression was motivated by some type of bias. Bias-based cyberaggression was associated with higher levels of several types of moral disengagement. Possible explanations and implications of the findings are discussed.