Moral sensitivity may play a role in dealing with ethical issues in ICUs. However, the moral sensitivity of adult ICU nurses in China and its predictors have not been well investigated. To analyse the moral sensitivity of intensive care unit (ICU) nurses and its predictors. A cross-sectional study through convenience sampling was conducted in the ICUs of five hospitals in China between November and December 2022. A total of 331 ICU nurses were recruited. Data were obtained using a self-developed socio-demographic characteristic questionnaire, the Moral Sensitivity Questionnaire, the Jefferson Scale of Empathy-Health Professionals and the Organizational Climate Scale for Nursing. The participating institutions received a link to the tools used for online data collection, which they then forwarded to nursing staff. The valid response rate was 96.98% (n = 321). The total mean moral sensitivity score of nurses was 43.04 ± 5.95. The mean scores for empathic ability and organizational climate for nursing were 91.97 ± 17.88 and 101.28 ± 14.77, respectively. Regression analyses revealed that the primary factors associated with moral sensitivity among critical care nurses included work tenure (p < .05), empathic ability (p < .001) and organizational climate (p < .001). High levels of moral sensitivity were found in critical care nurses in China. Work tenure, empathic ability and organizational climate were significant predictors of moral sensitivity in critical care nurses. To enhance the ethical sensitivity of ICU nurses, we suggest to strengthen the training of novice nurses so that they can better face the moral dilemma in clinical practice. In addition, organizational managers should also take measures to create a positive and harmonious working atmosphere, promote the application of moral knowledge in nursing practice and enhance their moral sensitivity.