One of the branches of ethics knowledge that has recently found a place in Iran is the field of professional ethics, which needs to be paid more epistemological attention. One of the rich sources in professional ethics is the teachings of Islam. But recognizing and promoting professional ethics based on Islam is not possible without analyzing the moral teachings of Nahj al-Balaghah. Considering this important point, in the present study, we intend to examine the principles of teacher professional ethics in the valuable book of Nahj al-Balaghah using the method of documentary analysis. The results show that Imam Ali (AS) has always paid attention to the discussion of ethics and moral principles and in many cases, his agents and companions, in particular and all human beings over time have commanded to observe them.The result of this kind of view of Nahj al-Balaghah leads us to the point that teachers, first of all, are fully aware of the moral teachings in every subject they are working on; Secondly, they should be inspired by their educational models in order to be effective in their work, and they should also be characterized by the necessary monotheistic knowledge and insight. The result of this approach by educators will be that educators, in any specialized field they are studying, look at religious-moral knowledge as a necessary knowledge for life, and become professional and committed people.