Empirical research has increasingly found evidence for the coexistence of animal abuse and various forms of interpersonal violence. Some researchers have even argued for a specific version of this relationship, namely, that individuals tend to move from violence toward animals, particularly in childhood, to subsequent violence toward humans. Others have suggested that the evidence for this graduation or progression hypothesis is weak and inconsistent, and that an approach to animal abuse that focuses on the link is misguided. This article begins by reviewing the research on the connections between animal abuse and interhuman violence. Then it critically assesses the evidence for and against the link, and discusses the issues and challenges facing future research in this area.