Background: Ethical leadership affects employees motivation, ability and willingness to work in a way that makes them more productive and makes additional efforts as it achieve employees job satisfaction, decreases employees levels of burnout and create an atmosphere that helps improve job performance level of workers. Aim of the study: to determine the effect of ethical leadership on nurses' job performance. Design: Descriptive research design. Setting: The study was conducted at Sohag University Hospital. Subjects: Nursing supervisors (N=25) and nurses (N=240).Tools: three tools for data collection used; 1) Demographic data sheet for nursing supervisors and nurses; 2) Ethical Leadership Questionnaire; and 3) Nurses Work Performance questionnaire Results: about (66.7%) of nursing supervisors had low levels for people orientation and (63.3%) of them had high level for fairness regarding ethical leadership behavior. About (83.37%) of nurses had high level of job performance for counterproductive work behavior. Conclusion: more than half of nursing supervisors had low levels of ethical leadership behavior. On the other hand more than three quadrants of nurses had high levels of job performance. There were a highly statistical significant differences between ethical leadership and all nurses job performance dimensions (P = 0.000) **. Recommendations: Conducting training programs to increase level of nurses' awareness of the concept, benefits and outcomes of ethical leadership.