The application of nanomaterials in the treatment of various human diseases is the most challenging area. These applications include drug delivery nanocarriers, nanoprobe-based detection/imaging of disease states and nanoparticle-based theranostics. This chapter summarizes the specific advantages of nanodrugs, types of nanomaterials that are approved as clinical nanodrugs and guidelines about chemical composition of nanomaterials for future development of clinical nanodrugs.