This paper explores moral sensitivity in Finnish secondary school teachers and students. Moral sensitivity comprises capacities to identify and interpret different kinds of situations in the ethical framework; it is the awareness of how our actions affect other people. In the teaching profession, teachers have to consider different lines of action in dealing with their students, parents, and colleagues. An important challenge is to become aware that moral issues are involved in these interactive relations. Moral sensitivity in teaching requires readiness to identify and solve moral dilemmas at school. In the learning process, students are exposed to different subjects and scientific issues defined by the curriculum. Moral sensitivity in learning includes awareness of moral dilemmas in the learning environment and capabilities to reflect on them with empathy and role-taking skills. Furthermore, learning should include critical reflection on scientific issues from an ethical point of view. The challenge for both teachers and students is to become aware of the ethical frameworks and the knowledge base that is guiding their moral reasoning. This paper presents some empirical findings of the moral dilemmas teachers and students have identified as relevant in their teaching and learning. A special emphasis is placed on the moral knowledge that guides their argumentation in justifying moral decision-making in these cases. (Contains 4 figures and 15 references.) (MKA)