This paper argues that professional ethics for teachers is not a form of moral education and that its content should not be taken primarily from the law on teacher morality. It claims that, since one part of ethical teaching is teaching one's subject with integrity, one source of ethics for teachers is the mastery of subject matter. Another source of ethical concepts for teachers is what is implicit in the pedagogical portion of teacher education. This part of the curriculum should be examined for its ethical content. Explicit instruction in ethics should emphasize concepts that are central to the work of teachers. Examples are due process, equity, privacy, intellectual honesty, freedom of expression, and legitimate authority. Emphasis should not be on generating rules to be followed. Instead instruction should focus on comprehension of concepts and their application to cases. A case method of teaching is recommended. © 1990.