Research ethics is a new field which comprises different areas. The goal is to bring science and ethics closer together, ensuring that past mistakes are no longer repeated. Right after the Second World War, ethics in research was considered an exclusive matter of medical studies. However, it is now an affirmation of human rights in the practice of scientific research in all areas of knowledge. In Brazil, the ethics review system has been active for over ten years and includes almost six hundred research ethics committees. This book presents the international debate and describes the characteristics of the Brazilian ethics review model.