Nanotechnology, in order to understand nanometer-sized physical, chemical and biological processes, includes studies for the regulation and control of matter at the molecular level. Recently, nanotechnology work, as in many areas, illustrates the significant developments in the field of health. Nanotechnology, at the molecular level to be monitored system that affect human and human being, repairing and restruction through improvement of human health protection and to increase the quality of patient care provided/would be. Besides, it is foreseen to be a source of hope for the early diagnosis and treatment of some diseases. All of these benefits, as well as the side effects of nanotechnology on human health are not yet known exactly. In this article, in the area of health could have positive effects, today in the literature on the harmful effects possible with the existing and potential developments in nanotechnology were discussed.