Purpose : The purpose of this study is to analyze the history of nursing and medicine as phenomena of knowledge/power from the viewpoint of Foucault. Method : The present study adopts the genealogical method by Foucault, which tries to unite languages and knowledge. Foucault who attempted to show that the basic ideas which people normally take to be permanent truths about human nature and society change in the course of history. Results : It has been emphasized that the development of modern health care has been due to the progressive efforts of medicine and to medical discoveries. Foucault examines the institutionalization of knowledge and the power exerted thereby, with special reference to the devices of social regulation and their function over the madness, the disease, the crime, and the sexuality. The concept of power is that it is exerted spontaneously in verbal behaviors of individuals through knowledge of everyday life such as definition of body or mind. Therefore as to the problem of knowledge/power, this study tries to understand the meaning of history of nursing and medicine through an analysis of the formation of text of history. In order to have authority in a power relation, the medical professional asserts that medical discourse is the most scientific knowledge. Conclusion : According to the above findings, it can be concluded that the body is also directly invested in a political field: power relations have an immediate hold upon it; they invest it, mark it, train it, torture it, force it to carry out tasks, to perform ceremonies, to emit signs. Therefore the devaluation of nursing care is reinforced by the medicine which has the legitimate authority through use of the political skills about the body.