Background Morality is a fundamental component of nurses’ daily work. Nurses’ cognitive tendencies toward moral disengagement in high-stress work environments can easily lead them to engage in counterproductive work behaviors that are not conducive to the organization. However, there is limited research on how to mitigate the impact of moral disengagement on counterproductive work behavior. Objective The objective was to explore the impact of moral disengagement on counterproductive work behavior, as well as the reverse regulatory mechanism of moral identity on (...) the relationship between moral disengagement and counterproductive work behavior. Research design This was a quantitative, cross-sectional study. Participants and research context From September to October 2023, nurses from emergency departments of major hospitals in Hunan Province were recruited, and 500 questionnaires were distributed and collected using the WeChat app Credamo Seeing Numbers. Ethical consideration All study procedures were approved by the Ethics Committee of Hunan Normal University (No. 2023-388). Findings Moral disengagement had a positive effect on counterproductive work behavior directed at the organization (CWB-O) as well as counterproductive work behavior directed at individuals (CWB-I). Moral identity was not significant in moderating the relationship between moral disengagement and CWB-O. Moral identity had an inverse moderating effect on the mechanism of action between moral disengagement and CWB-I. Conclusion Counterproductive work behavior guided by moral disengagement is detrimental to organizations, and moral identity can inhibit the effect of moral disengagement on CWB-I. Nursing administrators should focus on improving nurses’ moral identity and improving the healthcare workplace environment so that moral identity can better exert its inhibitory effect on counterproductive work behavior among nurses. (shrink)