Cancer is associated with an increase in cell number, alterations in mechanisms regulating new cell birth, or cell proliferation. Cancer is a major human health problem worldwide and is still the leading cause of death all over the world. The diagnosis and treatment of cancer have remained essentially unchanged for decades, and death rates are similar to what they were in the 1950s. Despite recent progress in understanding of the biology of cancer, the majority of cases are still diagnosed only after tumours have metastasized, leaving the patient with a grim prognosis. Till now, surgery, radiotherapy, and chemotherapy had been the standard therapies for tumour treatment. However, the application of all these methods is limited due to certain deficiencies. The application of nanotechnology in cancer is termed as nanooncology. Nanooncology includes both diagnostics and therapeutics. Nanotechnology has large potential in detection and treatment of cancer in its incipient stage. The basic aim in nanooncology is to create agents that are capable of detecting cancer as well as aid in the treatment of cancer.