Ethics is the branch of philosophy that examines the differences between right and wrong. Simply ethics is the study of the rightness of conduct. Aim of the study: to assess nurses' knowledge, practice regarding ethical and legal issues in critical care unit. Research design: A descriptive exploratory design was utilized. Subjects: include all available nurses working in critical care units Ain Shams University Hospitals, 40 nurses from both genders, with different ages, and at different educational levels and years of experience were selected for this study. Tools: (1) Nurses ethical and legal issues awareness questionnaire. (2) Ethical and legal observational checklist. Results: About two thirds of studied nurses had unsatisfactory level of knowledge, more than three quarters of them had unsatisfactory practice regarding ethical and legal issues in critical care units. Conclusion: Nurses had unsatisfactory level of knowledge and practice regarding ethical and legal issues in critical care units. There was statistically significant relation between knowledge, practice, and their demographic characteristics as regards: age, level of education and experience years. Recommendations: Furthers studies to evaluate the reflection of educational program regarding nurses' performance & consequently on the patient outcome. The study should be replicated on large sample & in different hospitals setting to generalize the results.