Nanomedicine is application of nanotechnology to diagnosis, treatment and prevention of diseases, in which multidisciplinary approaches are used combining chemistry, physics, biology, genetics, and medicine. Currently, there are a number of approved nanomedicines some of which have been developed to treat diseases using two main different approaches; passive or active targeting. Others include in vitro and in vivo diagnostic nanoparticles that have been shown to have many advantages compared to the traditional methods. Although there are some safety issues regarding development and use of nanoparticles in medicine and controversies surrounding the need for nanomedicine-specific regulations; many nanomedicines have been approved to date, and further improvements are being pursued with promising success. In this chapter, we summarise the use, advantages, current and future statuses of pharmaceutical and diagnostic nanomedicines, including ethical issues and regulations.