In this article, we examine the psychology of revenge. We begin by discussing challenges associated with defining revenge. We then review the relative costs and benefits associated with taking revenge. Although revenge can deter future harm, promote cooperation, and restore avengers’ self-worth and power, it can also contribute to conflict escalation and adverse psychological outcomes for avengers, such as depression and reduced life satisfaction. Next, we examine the prevalence of revenge. In distinguishing between the desire for revenge and act of revenge, we challenge the notion that the act of revenge is an automatic or pervasive response to injustice. We highlight four factors that influence whether victims of injustice choose to take revenge: the persistence of anger, perceptions of the costs of revenge, cultural and religious values regarding revenge, and the presence of external systems that can restore justice on behalf of victims.