Cancer is the leading cause of mortality worldwide. Treating the cancer is one of the major challenges in modern science as the drug delivery to solid tumors is a seminal challenge to develop more effective cancer therapies. A well-designed drug delivery system can potentially enhance the efficacy of a treatment by improving drug accumulation in the tumor. Application of nanotechnology to prevent and treat the cancer disease is known as nanomedicine. Cancer diagnosis and treatment can be achieved to a greater extent by the application of nanotechnology principles to biomedicine. Over these years targeted treatment for cancer has been greatly improved by the approaches based on nanotechnology. Nanoparticles have the potential to increase the specificity in treating cancer cells while leaving the healthy cells. The goal of this review is to discuss the current state of nanomedicine in the field of cancer detection and the subsequent application of nanotechnology to treat cancer by using nanoparticles such as dendrimers, quantum dots, nanocells, nanocrystals, and nanoshells for the detection and treatment of cancer.