We examined nurses’ perceptions of the ethical climate of their workplace and the relationships among the perceptions, medical error experience and intent to leave through a cross-sectional survey of 1826 nurses in 33 Korean public hospitals. Ethical climate was measured using the Hospital Ethical Climate Survey. Although the sampled nurses perceived their workplace ethical climate positively, 19% reported making at least one medical error during the previous year, and 25% intended to leave their jobs in the near future. Controlling for individual and organizational characteristics, we found that nurses with a more positive perception of the ‘patient’ dimension of ethical climate were less likely to have made medical errors. Nurses with a more positive perception of the ‘patient’, ‘manager’, ‘hospital’ and ‘physician’ dimensions of ethical climate were less likely to leave their current job. Enhancing workplace ethical climate could reduce medical errors and improve nurses’ retention in public hospitals.