This book comprehensively reviews the application of nanoparticles in cancer diagnosis and treatment. The introductory section provides a fundamental understanding of cancer biology, its global incidence and prevalence, and the intricate nano–bio interactions at the cellular level. The subsequent section discusses the pivotal role of nanoparticles in precise cancer detection, enhancing cancer imaging and serving as contrast agents for accurate diagnosis. It also presents cutting-edge nanotechnology-based methods for detecting HTLV-1 retroviruses. The following section covers the utilization of lipid-based nanoparticles, monoclonal antibodies, and advanced nanotherapeutics for targeted cancer treatments. This book is a useful resource for researchers, clinicians, and students in the fields of oncology and nanotechnology.