This book discusses approaches based on multifunctional and targeted theranostic nanomedicines for improving diagnosis and drug delivery. It explores nanomedicines based on nanocarriers like liposomes, ethosomes, niosomes, polymeric nanoparticles, lipidic nanoparticles, metallic nanoparticles, micelles, dendrimers, quantum dots, carbon-based nanomaterials including carbon nanotubes, carbon dots, carbon quantum dots, graphene oxide, and fullerene. This book reviews designing, conjugation, optimization, formulation and development, and scale-up of multifunctional and targeted theranostic nanomedicines. It examines major challenges in developing nanomaterials that can be applied to nanomedicine with high biocompatibility and biodegradability for diagnostic and therapeutic purposes. Lastly, it addresses the most promising approaches at both commercialization and regulatory steps for bringing theranostic nanomedicine from research laboratories to clinics for patient use.