We are interested in the development of metal-phenolic nanonetworks for biomedical applications. Metal-phenolic nanonetworks (MPNs), making use of the coordination between phenolic ligands and metal ions, have emerged as promising candidates for nanomedicine, most notably through the service as multifunctional theranostic nanoplatforms. MPNs present unique properties, such as rapid preparation, negligible cytotoxicity, and pH responsiveness. MPNs can be further modified and functionalized to meet specific application requirements. As for the tumor treatment, conventional chemotherapy, radiotherapy, Photodynamic therapy, and phototherapy can all be achieved by MPNs. As functional nanoplatform, MPNs can realize the combination of multimodal treatment strategies, which may lead to synergistic therapeutic effect.