Social rejection elicits profound feelings of distress. From an evolutionary perspective, the best way to alleviate this distress is to behave prosocially, minimizing the likelihood of further exclusion. Yet, examples ranging from the playground to the pub suggest rejection commonly elicits aggression. Opposing theoretical perspectives and discordant empirical results have left a basic question unanswered: does rejection more commonly elicit prosocial or aggressive behavior? We conducted three meta-analyses (one with studies measuring aggressive behavior; one with studies measuring prosocial behavior; and one with studies measuring both aggressive and prosocial behavior; N = 3864) to quantify: (1) the extent to which social rejection elicits prosocial or aggressive behavior and (2) potential moderating effects on these relations. Random-effects models revealed medium effects such that social rejection potentiated aggressive behavior (k = 19; d = 0.41, p < .0001) and attenuated prosocial behavior (k = 7; d = 0.59, p < .0001), an effect that remained consistent even when participants were given the option to behave prosocially or aggressively (k = 15; d = 0.71, p < .0001). These results cast doubt on the theory that rejection triggers prosocial behavior, and instead suggest it is a robust elicitor of aggression. Statement of Relevance: To our knowledge, these meta-analyses are the first to directly test whether social rejection elicits aggressive or prosocial behavior. By including a comprehensive collection of both published and unpublished research studies, and examining a wide variety of previously untested moderators, we show that social rejection robustly elicits aggressive behavior and inhibits prosocial behavior. Additionally, we demonstrate that aggressive behavior following social rejection is not simply a function of limited choices in response options. In fact, aggressive behavior was evoked even when the option to engage in prosocial behavior was provided. Furthermore, we conducted a comprehensive narrative review of the neural mechanisms underlying social rejection-elicited aggressive and prosocial behavior to supplement primary analyses. Overall, we believe that our work makes a critical theoretical contribution to the field.