We examine the influence of individuals’ propensity to morally disengage on a broad range of unethical organizational behaviors. First, we develop a parsimonious, adult-oriented, valid, and reliable measure of an individual's propensity to morally disengage, and demonstrate the relationship between it and a number of theoretically relevant constructs in its nomological network. Then, in 4 additional studies spanning laboratory and field settings, we demonstrate the power of the propensity to moral disengage to predict multiple types of unethical organizational behavior. In these studies we demonstrate that the propensity to morally disengage predicts several outcomes (self-reported unethical behavior, a decision to commit fraud, a self-serving decision in the workplace, and supervisor- and coworker-reported unethical work behaviors) beyond other established individual difference antecedents of unethical organizational behavior, as well as the most closely related extant measure of the construct. We conclude that scholars and practitioners seeking to understand a broad range of undesirable workplace behaviors can benefit from taking an individual's propensity to morally disengage into account. Implications for theory, research, and practice are discussed.