It has long been hypothesized that feelings of inferiority or low self-esteem lead individuals to aggress against those they view as being threatening. However, recent studies suggest that it is not just the level of self-esteem but stability that is relevant to understanding this process. As such, researchers have looked to related constructs, such as narcissism, in trying to understand aggressive behaviors. Narcissism is characterized by a dissociation between an unconscious sense of inadequacy and a conscious feeling of superiority. A large number of studies examining the relationship between narcissism and violence have recently been published within both clinical and student populations. This review aimed to systematically collate the findings of such studies and integrate them within current theories of violence. Electronic literature databases such as Web of Science, MEDLINE, PsychINFO, EMBASE, Cochrane databases, and LexisNexis (legal database) were searched to identify studies examining the relationship between narcissism and violence. Twenty articles were included in this review, describing 25 separate samples. Findings suggest that narcissism is relevant in understanding aggression and violence. This was consistent across both clinical and nonclinical populations and therefore does not appear to be an artifact of studying either very violent or student samples. Evidence from student samples strongly supported the association between narcissism and aggression following an ego threat, while studies using clinical samples did not examine the effect of an ego threat. These findings may have an impact on how we understand, predict, and reduce violence.