Ethical concerns are a major part of the clinical practice of emergency medicine. The emergency physician must make hard choices, not only with regard to the scientific/technical aspects but also with regard to the moral aspects of caring for emergency patients. By the nature of the specialty, emergency physicians face ethical dilemmas often requiring prompt decisions with limited information. This manual identifies important moral principles and values in emergency medicine. The underlying assumption is that a knowledge of moral principles and ethical values helps the emergency physician make responsible moral choices. Neither the scientific nor the moral aspects of clinical decision making can be reduced to simple formulas. Nevertheless, decisions must be made. Emergency physicians should, therefore, be cognizant of the ethical principles that are important for emergency medicine, understand the process of ethical reasoning, and be capable of making rational moral decisions based on a stable framework of values.