This research empirically examined the impact of psychological ethical climates on unethical behavior within organizations via a survey-based quantitative study of working adults in U.S. firms. Ethical climate types within an organization were hypothesized to influence individual propensity to engage in unethical behavior as reflected by moral disengagement, ethical judgments, and unethical pro-organizational behavior. The moderating influence of moral identity and situational strength on these relationships was also hypothesized. Results showed that egoism climate was positively correlated and principle climate was negatively correlated with the unethical behaviors in this study. Further, egoism climate was found to have the strongest and most consistent correlations with these behaviors, whereas benevolence climate was found to have no significant correlations with these behaviors. Moral identity internalization, but not moral identity symbolization, was found to have significant correlations with unethical behavior as well as moderating effects on the relationships between ethical climates and unethical behavior. Findings suggest that further study of egoism climates and moral identity internalization is of particular importance for researchers seeking to better understand the individual and contextual factors that influence unethical behavior and for organizations seeking to minimize unethical behavior and maximize desirable outcomes. Theoretical and practical implications and future research directions are discussed.