OBJECTIVE: Nanotechnology and its applications in medicine made us live a new era of healthcare, particularly in oncology. The objective of this paper is to review the contribution of nanotechnology in clinical use of contrast agents for gastrointestinal cancer diagnosis and follow-up and to offer an overview of the impact of nanotechnology in the management of cancer. MATERIALS AND METHODS: In this regard, we reviewed the main areas of expertise where nanotechnology has contributed to the improvement of diagnostic methods (CE-US, CE-CT, MRI), along with the therapeutic applications that nanoparticles can have. Last but not least, the article highlights the potential that theragnostic molecules can have in the diagnosis and treatment of neoplasia, including those in an advanced stage. RESULTS AND CONCLUSIONS: Nanomedicine has the ability to improve the specificity and sensitivity of cancer diagnosis, together with the enhancing of the systemic cytostatic effect by developing nano bioconjugates that have a wider effect, higher tumor selectivity and thus, lower systemic toxicity.