BACKGROUND: Cancer is one of the major leading causes of death worldwide and its prevalence will be higher in the coming years due to the progressive aging of the population. The development of nanocarriers in oncology has provided a new hope in the fight against this terrible disease. OBJECTIVE: Among the different types of nanoparticles which have been reported in the scientific literature, mesoporous silica nanoparticles (MSNs) are very promising materials due to their inherent properties such as high loading capacity of many different drugs, excellent biocompatibility and easy functionalization. RESULTS: This review presents the current state of the art related to the development of mesoporous silica nanocarriers for antitumoral therapy paying special attention on targeted MSN able to selectively destroy tumoral cells, reducing the side damage in healthy ones, and the basic principles of targeting tumoral tissues and cells. CONCLUSIONS: MSNs constitute a promising nanomaterial for drug delivery applications in antitumoral therapy as a consequence of its unique properties such as excellent biocompatibility, high loading capacity, robustness, easy production and existence of multiple strategies for their functionalization with a myriad of bio-organic moieties. In the coming years, the clever application of this material would provide novel alternatives for the treatment of this complex disease.