Nanotechnology for cancer therapy is playing a pivotal role in dramatically improving current approaches to cancer detection, diagnosis, and therapy while reducing toxic side effects associated with previous cancer therapy. A widespread understanding of these new technologies will lead to develop the more refined design of optimized nanoparticles with improved selectivity, efficacy and safety in the clinical practice of oncology. This review provides an integrated overview of applications and advances of nanotechnology in cancer therapy, based on molecular diagnostics, treatment, monitoring, target drug delivery, approved nanoparticle-based chemotherapeutic agents, and current clinical trials in the development of nanomedicine and ultimately personalized medicine.