Authors have made an educational program aiming to reduce medical accidents in hospitals. The new program consists in watching a video/DVD in which the parents of a child victim of a medical accident talk of their experience and feeling about the accident, and in discussing about the Video/DVD. This paper aims to show the positive effects of the educational program and also claims that the positive effects of our program largely comes from the discussion after watching the video about how they should attend to their patients among nurses and medical doctors. In other words, collective dialogues about the ethical matter should play a great role in the improvement of the ethical consciousness in an organization. Especially, the result of the program held among the inexperienced nurses is more influenced by the group discussion than the personal beforehand belief about the ethical matter in their works.