In this article, we describe how envy motivates deception. We find that individuals who envy a counterpart are more likely to deceive them than are individuals who do not envy their counterpart. Across both a scenario and a laboratory study, we explore the influence of envy in a negotiation setting. Negotiations represent a domain in which social comparisons are prevalent and deception poses a particularly important concern. In our studies, we induce envy by providing participants with upward social comparison information. We find that upward social comparisons predictably trigger envy, and that envy promotes deception by increasing psychological benefits and decreasing psychological costs of engaging in deceptive behavior. We discuss implications of our results with respect to negotiations and the role of emotions in ethical decision making.