People routinely engage in dishonest acts without feeling guilty about their behavior. When and why does this occur? Across four studies, people justified their dishonest deeds through moral disengagement and exhibited motivated forgetting of information that might otherwise limit their dishonesty. Using hypothetical scenarios (Studies 1 and 2) and real tasks involving the opportunity to cheat (Studies 3 and 4), the authors find that one's own dishonest behavior increased moral disengagement and motivated forgetting of moral rules. Such changes did not occur in the case of honest behavior or consideration of the dishonest behavior of others. In addition, increasing moral saliency by having participants read or sign an honor code significantly reduced unethical behavior and prevented subsequent moral disengagement. Although dishonest behavior motivated moral leniency and led to forgetting of moral rules, honest behavior motivated moral stringency and diligent recollection of moral rules.