In this edited book, we highlight the central players in the Bionanotechnology field, which are the nanostructures and biomolecules. The book starts by describing how nanostructures are synthesized and by describing the wide variety of nanostructures available for biological research and applications. Also shown are the techniques used to synthesize a wide variety of biological molecules. Next, there is a focus on the assembly of nanostructures with biological molecules, which could lead to the design of multi-functional nanosystems. In the following chapters, examples of the unique properties of nanostructures are provided along with the current applications of these nanostructures in biology and medicine. Some applications include the use of gold nanoparticles in diagnostic applications, quantum dots and silica nanoparticles for imaging, and liposomes for drug delivery. In the final chapters of the book, the toxicity of nanostructures are described. This book provides broad examples of current developments in Bionanotechnology research and would be an excellent introduction to the field.