Introduction: Nurses experience a variety of morally distressing situations while caring for the elderly. Ethical behavior can be a way to reduce moral distress. Therefore, the present study aimed to determine the relationship of ethical behavior with severity and frequency of moral distress among nurses working in government hospitals in Bojnourd and nursing homes in Bojnourd and Mashhad. Materials and Methods: The present descriptive-analytical study was conducted based on the census method on 454 nurses working in Bojnourd teaching hospitals and nursing homes in Bojnourd and Mashhad. Data collection tools included Corley's moral distress scale and the questionnaire of ethical conduct components based on the theory of virtue ethics developed by Nikkhah et al. (2015). The validity and reliability of this questionnaire have been confirmed, and ethical considerations were taken into account. Data were analyzed in SPSS software (version22) using descriptive statistics, tables, and graphs. Results: In the current study, the majority of participants (80.8%) were female with a mean age of 7.75±31.68 years. Moreover, virtue-oriented ethical conduct was negatively and weakly correlated with the severity and frequency of moral distress (r=-0.11). The scores of severity and frequency of moral distress in nurses were obtained at 2.6 and 2.4, respectively. There was also a strong positive correlation between the frequency and severity of moral distress (r =0 .848). The score of ethical behavior in nurses was calculated at 4.1. Conclusion: Virtue-oriented ethical behavior in the organization can be effective in reducing nurses' moral distress. Therefore, in order to reduce moral distress in nurses, it is suggested that managers devote special attention to the promotion of virtue-oriented ethical behavior. Moreover, appropriate incentive policies should be designed and programmed to promote virtue-oriented ethical behavior in any organization. Keywords: Moral distress, Ethical behavior, Theory of virtue ethics, Nurse, Elderly, Statement of the problem