We present a meta-analytic investigation of the theoretical mechanisms underlying why experienced workplace aggression is harmful to the three core performance outcomes (i.e., task performance, citizenship behavior, and deviant behavior). Through a comprehensive literature review of 405 empirical articles, we first extract and identify five prominent theoretical mechanisms: relationship quality, justice perception, psychological strain, negative affect, and state self-evaluation. By synthesizing evidence from these articles, which include 471 unique samples from 36 countries or regions (