This book discusses the potential of magnetic nanoparticles in cancer therapy. It reviews the synthesis of magnetic nanoparticles - which, due to their small size and processability, have become widely used in various biomedical applications - and their role in cancer diagnosis, drug delivery, and personalized medicine. It presents the applications of magnetic nanoparticle in the destruction of tumor cells by heating them to their apoptosis threshold. It also introduces the new perspective in the development of magnetic field induced drug release in the cancer treatment. Importantly, the book covers the innovative three arm approach in cancer treatment by magnetic nanoparticles through inducing apoptosis, activating the immune response, and targeted-drug delivery. It highlights various novel approaches to improve the biocompatibility, half-life, and biodegradability of magnetic nanoparticles. In closing, the book offers comprehensive descriptions of numerous challenges involved in applying magnetic nanoparticles to cancer treatment.