Substantial empirical evidence supports low resting heart rate (HR) as the best replicated psychophysiological correlate of aggression [Ortiz and Raine, 2004]; however, researchers continue to debate the explanatory mechanisms of the phenomenon. Sensation seeking has been proposed as a possible outcome of low resting HR that may lead to aggressive tendencies but findings have been inconsistent in terms of showing a relationship between sensation seeking and aggression. A meta-analysis was conducted on 43 independent effect sizes, from studies with a total of 32,217 participants, to test the hypothesis that sensation seeking would be positively related to aggression across studies. A significant overall effect size was found (d = .1935, P<.001), supporting the hypothesis. Moderator analyses revealed that the relationship differed based on participant and methodological characteristics, such as participant age and the nature of the aggression measurement; however, these conclusions are limited by the uneven number of studies in many of the moderator classes. Overall, the findings provide support for higher levels of aggression in high sensation seekers and have theoretical implications for arousal theory. Further research on the links between arousal, sensation seeking and aggression can inform clinicians about potential interventions. Aggr. Behav. 37:81–90, 2011. © 2010 Wiley-Liss, Inc.