Nanomedicine has become an important development direction of modern medicine, and provides a new way for cancer theranostics. To extend the superior physicochemical property of nanomedicine and enhance their role in cancer theranostics, various strategies have been proposed. Among them, the introduction of oxygen vacancies can enhance the separation of electron-hole pairs and improve the nanomaterials' catalytic activity, which is beneficial for cancer diagnosis and treatment. This review briefly summarized the formation mechanism and preparation methods of various oxygen vacancy nanomaterials. Then, the effect and application of various oxygen vacancy nanomaterials, such as iron, manganese, titanium, zinc, bismuth, tungsten, cerium, and molybdenum-based nanomaterials in enhancing cancer theranostics were highlighted. At last, the prospect and challenges of oxygen vacancy nanomaterials were discussed. This review provided an overview of the relevant information on oxygen vacancy in cancer theranostics, and further promoted the development of cancer nanomedicine.
