This descriptive correlational study aimed to examine the impact of moral courage and ethical climate on moral distress among clinical nurses. Data were collected from August to September 2024, through an online survey distributed to nurses working at two tertiary hospitals and one general hospital in a city in South Korea. The results indicate that the mean moral courage, ethical climate and moral distress were 3.20 ± 0.58, 3.42 ± 0.52, and 78.22 ± 53.89, respectively. Multiple regression revealed that factors affecting moral distress among clinical nurses included years of clinical experience (β=.23, p=.014), moral courage (ß=.40, p<.001) and ethical climate (β=-.44, p<.001).These variables explained 22% of the variance in moral distress. These findings suggest that there is a need for institutional strategies to improve the ethical climate and to support nurses' moral courage in order to alleviate moral distress.