The study of the legal framework regulating the activities of the Ethics Committees in the Member States of the European Union outlines several key factors forming the basis of the activity of the Ethics Committees. Compliance with the ethical principles of behaviour by physicians, patients, patients relatives, patient organizations and by the society as a whole requires professionals dealing with medical ethics and law to form, defend and bring to the knowledge and implementation an ethical code of behaviour of all participants in clinical trials as well as in the provision of medical services in general. The modern legal framework in Bulgaria, regulating the nature, functions and powers of the ethics committees, is complex and multi-layered, including both constitutional law and a number of acts at the law and bylaw level. Ethical committees set up in medical establishments aim to help physicians and other medical and non-medical specialists in the hospital, patients and their families coping with the ethical and legal dilemmas they face in everyday life. The results of a survey conducted among 149 medical specialists and 269 patients working and being treated in three different medical establishments in the country show that there is a low level of awareness of the types of ethical committees and their functions. 51% of the questioned medical specialists and 62.5% of the questioned patients replied that they were not aware when issues could be referred to the ethics committees in the country. The analysis of the regulation of the activities of ethics committees in the healthcare systems within the EU and in the health system in Bulgaria shows that there is a need to optimize the activity of the ethics committees operating on the territory of the country.