Background Ethical sensitivity is a prerequisite for ethical nursing practices. Efforts to improve nurses’ ethical sensitivity are required to correctly recognise ethical conflicts and for sound decision-making. Because an emerging infectious disease response involves complex ethical issues, it is important to understand the factors that influence public health nurses’ ethical sensitivity while caring for patients with COVID-19, an emerging infectious disease. Objectives This study aims to identify the relationship between nursing professionalism, the organisation’s ethical climate, and the ethical sensitivity of (...) nurses who care for emerging infectious disease patients in Korean public health centres. Further, it sought to identify factors influencing ethical sensitivity and the mediating effect of the organisational ethical climate to inform guidelines and improve ethical sensitivity. Research design This was a cross-sectional descriptive study. Participants and research context Data were collected from February 3 to 8 March 2021. Participants included 167 nurses caring for patients with COVID-19 in public health centres in South Korea. Ethical consideration This study was approved by the Institutional Review Board of the Chung-Ang University and followed the principles of research ethics. Results The factors influencing ethical sensitivity were working at a COVID-19 disease direct response department, nursing professionalism, and organisation’s ethical climate. The organisation’s ethical climate showed a partial mediating effect on the influence of nursing professionalism on ethical sensitivity. Conclusion Our findings show that nurses’ ethical sensitivity can be improved by refining the organisation’s ethical climate and nursing professionalism. (shrink)