Avicenna wrote many great books and articles such as Canon of Medicine which is his most important medical work. This study has been conducted in order to provide the necessary information on Avicenna's adherence to ethical principles and ethical norms in Canon. Three aspects including his medical practice, researches and philosophical attitude have been studied. Avicenna offers some valuable guidelines on the ethics in medicine in Canon. The first necessary condition for the practice of medicine is to comprehend medicine. Congruently, Avicenna emphasizes in his book that the doctor must be masterful. The use of scientific resources and valid information with citation to the references is one of the ethical subjects that are highlighted in this book. Avicenna has put much emphasis on ethical principles as a religious issue in medical practice. He believed in Islam and Islamic ethics and felt responsible toward God and his creations including humans Although in Canon there is no chapter specifically devoted to medical ethics, there are numerous ethical references that focus on humans as the main target of medical activities. It offers recommendations regarding ethical issues such as how to treat patients and minimize hazards. In brief, the book of Canon represents many humanistic ideas.