Toxic leadership is becoming increasingly common in healthcare organizations and there is strong need for studies focusing on organizational factors that can trigger revenge. Additionally, how psychological well-being functions in shielding against toxicity has not been adequately studied. Hence, this study aims to examine the relationship between toxic leadership and vengeful behaviors of nurses, along with the contingency of psychological well-being on the relationship during the COVID-19 pandemic. In this exploratory cross-sectional study, we attempt to examine the antecedent effect of toxic leadership on vengeful behaviors based on self-reports from 311 nurses. Using partial least squares and moderation analyses, the results show that toxic leadership is an important antecedent of vengeful behaviors among nurses. However, the results provide no statistical evidence to support a moderating role of psychological well-being in the relationship between toxic leadership and vengeful behaviors. This study reveals that nurses exposed to toxic behaviors by their superiors are more likely to engage in vengeance and highlights the fact that nurses are suffering psychologically during the pandemic.