Aim This study demonstrates the effect of academic nurses' perceptions of ethical work climate on their organizational citizenship behaviour. Background Establishing healthy relationships in organizations and ensuring organizational effectiveness depend on workers' perception of organizational ethics and voluntary behaviours that improve their organizations. Methods This study was conducted with 644 academic nurses working in public institutions of higher education that offer nursing education at the undergraduate level in Turkey. The data were collected using a sociodemographic characteristics form, the Ethical Climate Scale and the Organizational Citizenship Behaviour Scale. The data were evaluated using statistical software. Approvals for the study were obtained from the institutions and their ethics committees, and the participants' consent was obtained. Results This study found there was a significant relationship between academic nurses' perception of ethical work climate and their organizational citizenship behaviour. Ethical work climate based on social responsibility had the most effect on organizational citizenship behaviour. Conclusions Academic nurses' perceptions of ethical work climate affect their organizational citizenship behaviour. Implications for Nursing Policy Academic nurses should act in accordance with the laws and both professional and personal moral codes in the work environment, take into account team and institutional interests, be aware of their social responsibilities and be efficient. In this way, they can provide an ethical work environment and be a good organizational citizen based on volunteering and courtesy, thinking about team members, acting with advanced task awareness and supporting the development of the organization.