Although the “war on cancer” is now in its fourth decade and despite much progress has been made in categorizing the environmental causes and cellular and molecular biological basis for this dreaded disease, we still do not have a precise understanding of the differences between a cancer cell and its normal counterpart. If we do not understand cancer, we cannot control, conquer, and eliminate it. The completion of the human genome sequence and its subsequent improvements in the sequence data are important steps to fully comprehend cancer cell biology. Nanotechnology, a new, novel focus of research evolved from the convergence and coalescence of many diverse scientific disciplines and as a general term for the creation, manipulation, and application of structures in the nanometer size range. In this article, Nano medicine aspects of nanotechnology will be stressed and will cover areas such as drug delivery systems and new drug therapies as they relate to cancer. One of the ultimate goals of Nano medicine is to create medically useful Nano devices that can function inside the body. It is envisioned that Nano devices will be hybrids of biologic molecules and synthetic polymers that can enter cells and the organelles to interact directly with DNA and proteins. Additionally, Nano medicine will have an impact on the key challenges in cancer therapy: localized drug delivery and specific targeting. Among the newly developed Nano medicine and Nano devices such as quantum dots, nanowires, nanotubes, Nano cantilevers, and Nano pores, Nano shells and nanoparticles are the most promising applications for various cancer treatments.