Nanotechnology has revolutionized cancer therapy by introducing advanced drug delivery systems that enhance therapeutic efficacy while reducing adverse effects. By leveraging various nanoparticle platforms-including liposomes, polymeric nanoparticles, and inorganic nanoparticles-researchers have improved drug solubility, stability, and bioavailability. Additionally, new nanodevices are being engineered to respond to specific physiological conditions like temperature and pH variations, enabling controlled drug release and optimizing therapeutic outcomes. Beyond drug delivery, nanotechnology plays a crucial role in the theranostic field due to the functionalization of specific materials that combine tumor detection and targeted treatment features. This review analyzes the clinical impact of nanotechnology, spanning from early-phase trials to pivotal phase 3 studies that have obtained regulatory approval, while also offering a critical perspective on the preclinical domain and its translational potential for future human applications. Despite significant progress, greater attention must be placed on key challenges, such as biocompatibility barriers and the lack of regulatory standardization, to ensure the successful translation of nanomedicine into routine clinical practice.