<p>Transition Metal Oxides (TMOs) are a versatile class of nanomaterials with unique physicochemical, optical, and electronic properties, making them ideal for catalysis, electronics, optics, and biomedical applications. These properties arise from their d-shell electron configurations, enabling a wide range of bonding states, from conductive to insulating. This review explores recent advances and developments in TMOs synthesis techniques such as vapor-phase growth, electrochemical deposition, and hydrothermal processes. Subsequently, we discussed various functionalization strategies, such as covalent bonding, electrostatic interactions, and hybrid material integration, to further improve their stability and targeted functionality. We comprehensively reviewed their therapeutic applications of key TMOs: iron oxide, zinc oxide, titanium oxide, and manganese oxide. Then we also discussed the diagnostic applications of TMO, namely oxides of iron, manganese, titanium, tin, tungsten, and zinc. Ultimately, we provided insight into the toxicity of TMO and alternative strategies to overcome. We also discussed the current challenges and future research directions to be investigated.</p> Graphical Abstract <p></p>