Nanotechnology is a multidisciplinary endeavor, not only because it involves the joint expertise of physicists, chemists, biologists, engineers, and other natural scientists but also because sociology, law, philosophy, and history of science are also part of the game. In fact, the mantra of the nanoworld is, do not repeat the errors of the past! Public perception of this novel technological field is constantly monitored, and increasing fundings are devoted to studying the impact on human health and the environment of new materials and devices. New regulations have to be drafted and implemented. Borders between disciplines are constantly crossed, just as national borders are. In a global economy, nanotech products will reach every corner of the world. And not everywhere does the same perception of risk and benefits exist. Also, the extremely fast development of applications makes it difficult to assess risk and benefits and to introduce timely regulations. This session will bring together natural scientists as well as regulation experts from both sides of the Atlantic, to explore and compare U.S. and European attitudes toward nanoscience and nanotechs. Scientists will provide introductory talks on the present state of the art in nanotechnology and foreseeable developments. Regulations experts will discuss existing and planned intervention in the areas of public and work safety, consumers' health, and environmental protection.