Workplace mistreatment is a pervasive issue that has a host of deleterious consequences for those who experience it. While scholars have suggested that observers can help alleviate negative consequences of mistreatment by supporting targets, recent meta-analyses show that this is not always the case. We suggest that one of the reasons for negative observer reactions toward targets of mistreatment may lie in the potential of the mistreatment incident to cast a ‘mark’ on the target. Drawing on stigma theory, we posit that mistreatment can be a source of stigma for the targets, which, in turn, can prompt observers to react in ways that signal that they are not like and/or not affiliated with the target. Integrating insights from destigmatization literature, we further examine the role of target responses in countering the stigmatizing effects of mistreatment. Across three studies, we explore the content of stigma, the stigmatizing potential of mistreatment and its downstream consequences (e.g., target avoidance, negative gossip about the target), and the role of target responses in lessening stigma. From a theoretical perspective, our research illuminates identity-related implications of experienced mistreatment. Most importantly, from a practical perspective, our findings shed light on the role of target responses in alleviating these negative effects.