This article provides a conceptual framework for studying the influence of mood on managerial ethical decision making. We draw on mood-congruency theory and the affect infusion model to propose that mood influences managerial ethical decision making through deliberate and conscious assessments of the moral intensity of an ethical issue. By accounting for proscriptive and prescriptive morality—i.e., harmful and prosocial behavior, respectively—we demonstrate that positive and negative mood may have asymmetrical and paradoxical effects on ethical decision making. Specifically, our analysis suggests that individuals in a positive mood will be more likely to engage in prosocial behavior but less likely to refrain from activities that have harmful consequences for others, whereas individuals in a negative mood will be more likely to avoid activities that put others at risk or harm but at the same time less prone to engaging in activities that have positive consequences for others. Importantly, we account for the context within which managers make their decisions by examining how situational strength may moderate the influence of mood on managerial ethical decision making. Finally, we discuss how organizations can leverage the double-edged sword effect of mood on ethical decision making and prevent, control and manage the risk of unethical decision making on the part of managers.