In the fast-developing field of nanomedicine, a broad variety of materials have been used for the development of advanced delivery systems for drugs, genes, and diagnostic agents. With the recent breakthroughs in the field, we are witnessing a new age of disease management, which is governed by precise regulation of dosage and delivery. This book presents the advances in the use of metal-based and other nanomaterials for medical imaging, diagnosis, theranostics, and drug delivery.