Cutting-edge research in nanomedicine dominates studies in drug delivery, medical imaging, and the development of new devices. Materials and devices the size of molecules, and even individual atoms, make it possible to see a tumor when it is no more than a few atoms in size. By using material in this size range, drugs can go directly to tumors or inflamed arteries, bypassing healthy tissue. In this interview Norris Alderson of the Food and Drug Administration discusses the present and future state of nanomedicine as it applies to health care, taking into consideration benefits, risks, and how much is still unknown.