Cancer is one of the most prevalent causes of mortality worldwide. The arena of cancer diagnosis and therapy has undergone a tremendous revolution since the development of nanotechnology. Due to their nanosize and biocompatibility, nanoparticles are extensively employed for gene therapy and targeted drug delivery. Nanotechnology-based approaches have also shown promising advancements in the utilization of extracellular vesicles for cancer diagnosis, prognosis, and therapy. Apart from this, the CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated protein 9)-based nanotherapy and the development of therapeutic nanovaccines have also demonstrated encouraging results in revolutionizing cancer treatment. Nanotechnology-based molecular imaging and contrast agents can detect cancer at very early stages, allowing for prompt treatment and better patient outcomes. Although nanoparticles offer multiple benefits for drug administration, they additionally possess certain pharmacokinetic limitations, such as body clearance, restricted tissue penetration, confrontation with biological barriers, biodistribution, and accumulation. However, improvements in nanoparticle design are intended to resolve safety issues and enhance the therapeutic effects of these particles in a variety of disease complications. While nanotechnology has demonstrated immense potential in the treatment and diagnosis of cancer, there are still several challenges to overcome, including guaranteeing the safety of nanomaterials, taking into account regulatory issues, and creating scalable and affordable solutions. Nevertheless, new developments in nanotechnology and current research hold promise for further revolutionizing cancer detection and treatment.