Background In order to achieve the goals of the healthcare system, nursing managers are required to comply with ethical principles in decision-making. In complex and challenging healthcare settings, it is shown that the managers’ mere awareness of ethics does not suffice and managers need to be sensitive toward making ethical decisions. Aim To explore nursing managers and their sensitivity toward ethical decision-making by analyzing their related experiences. Method The current study has been conducted in Iran in 2017 through a qualitative (...) content analysis approach. Nineteen nurse managers were selected purposefully from different hospitals in Tehran. Data were collected using semi-structured, in-depth, face-to-face interviews, and after transcription, they were analyzed according to the Graneheim and Lundman method. Ethical considerations The research was approved by the ethics committee of Tarbiat Modares University, Tehran, Iran. Participants were informed about the purpose of the study and submitted written informed consents regarding their participation. The principle of autonomy, confidentiality, and anonymity was taken into account in data collection. Results Fifteen subcategories, three categories (assertiveness, commitment, and insight), and one theme of excellent decision-making were the results of data analysis. Discussion Findings showed that nursing managers’ sensitivity to ethical decision-making allows them to make the best decision by insight, commitment, and assertiveness. Making a morally excellent decision ensures that ethical principles are followed in the healthcare system. Conclusion Considering that most managers are committed to making ethical decisions, it is required to develop the scope of their insights even further using a professional management and ethical principles training program. Also, by addressing some of the ethical barriers at personal and organizational levels, the assertiveness in managers can be improved, which in turn can facilitate their ethical decision-making. (shrink)