Using meta-analysis, we compare three attitudinal outcomes (i.e., job satisfaction, affective commitment, and turnover intent), three behavioral outcomes (i.e., interpersonal deviance, organizational deviance, and work performance), and four health-related outcomes (i.e., general health, depression, emotional exhaustion, and physical well being) of workplace aggression from three different sources: Supervisors, co-workers, and outsiders. Results from 66 samples show that supervisor aggression has the strongest adverse effects across the attitudinal and behavioral outcomes. Co-worker aggression had stronger effects than outsider aggression on the attitudinal and behavioral outcomes, whereas there was no significant difference between supervisor, co-worker, and outsider aggression for the majority of the health-related outcomes. These results have implications for how workplace aggression is conceptualized and measured, and we propose new research questions that emphasize a multi-foci approach. Copyright © 2009 John Wiley & Sons, Ltd.