© 2022 John Wiley & Sons, Ltd.While scholars have debated whether environmental factors (e.g., air pollution) can prompt unethical behavior (e.g., crime), we argue that the COVID-19 pandemic provides a unique opportunity to inform this theoretical debate by elaborating on why these effects may occur, identifying how they can be overcome, and addressing methodological issues. Drawing on appraisal theories of emotion, we argue that appraising COVID-19 (i.e., an environmental factor) as a threat can elicit anxiety. This can focus employees on their own self-interest and prompt cheating behavior (i.e., unethical workplace behavior). However, we propose that these detrimental effects can be attenuated by prosocial messages (i.e., highlighting the meaningful and positive impact that employees' work can have on others). Our predictions were supported using a two-wave survey (N = 396) and an experiment (N = 163) with samples of full-time employees during the COVID-19 pandemic. Theoretically, our studies inform this ongoing debate by highlighting the importance of state anxiety and self-interest as key mechanisms and that drawing peoples' attention towards others can serve as a boundary condition. Practically, we provide insight into the ethical costs of COVID-19 in the workplace and identify a simple yet effective strategy that organizations can use to curtail workplace cheating behavior.