This book reviews the use of theranostic nanoparticles for cancer applications over the past decade. First, it briefly discusses the challenges and limitations of conventional cancer treatments, and presents an overview of the use of nanotechnology in treating cancer. These introductory chapters are followed by those exploring cancer diagnosis and a myriad of delivery methods for nanotherapeutics. The book also addresses multifunctional platforms, treatment monitoring, and regulatory considerations. As a whole, the book aims to briefly summarize the development and clinical potential of various nanotheranostics for cancer applications, and to delineate the challenges that must be overcome for successful clinical development and implementation of such cancer theranostics.