The purpose of this paper is to express Avicenna's standpoints in the area of teachers' professional ethics. Making use of a qualitative approach and a descriptive-analytic method, this study attempted to describe and analyze Avicenna's viewpoints on prerequisites of teaching profession by the help of the available resources. In general, the results showed that skillful teacher needs to possess admirable ethical characteristics in his individual and social dimensions. He should attempt to educate his own soul before making any effort in educating others considering some important points. It is better for him to have prudence in all his affairs. He should not try to educate anybody before being acquainted with his/her traits. He also should be generous and faithful toward the others. Eventually, it is expected from such a kind of teacher to gain a very high level of skillfulness in advising and guiding the learners.