Cancer research world is positively looking to bio-nanotechnology to find best solutions for a complete cure from cancer, which is not possible with current established treatment methods and nowadays lot of research work is going on in this field. However, during the past more than one decades of our research in the "Nano imaging and drug delivery" field against cancer, though the authors came across many interesting papers and reviews, the authors couldn't see a highly useful book, which can provide very concise but still discussing all fields that related to nano cancer research in diagnosis and Drug delivery. To fill this vacuum, the authors bring forward the book "Bio Nanotechnology in Cancer: Diagnosis and Therapy". This book has been mainly divided into two parts primarily to accommodate the latest bio-nano research in the cancer related field; namely, Nanodiagnostics and Nanotherapeutics and having 12 Chapters in total. This book starts with an Introduction chapter to provide the back ground of Cancer and Cancer therapy.