Metal-organic frameworks (MOFs) have been scaled down to nanometer sizes, leading to the development of nanoscale metal-organic frameworks (NMOFs) for biomedical applications. NMOFs offer several advantages over conventional nanomedicines, including structural and chemical diversity, high loading capacity, and intrinsic biodegradability. They can be synthesized under relatively mild conditions and tuned to optimize particle properties. NMOFs can be loaded with active agents through two main strategies: incorporation during synthesis or post-synthesis loading. NMOFs have been explored as MRI contrast agents due to their ability to carry large amounts of paramagnetic metal ions, with Gd3+, Mn2+, and Fe3+-containing NMOFs showing excellent efficacy. They have also been used for optical imaging and X-ray CT imaging by incorporating luminescent or high-Z element building blocks. In drug delivery, NMOFs have been used to encapsulate anticancer drugs, such as cisplatin prodrugs, with sustained release and comparable efficacy to free drugs. Surface modification with silica coatings or organic polymers improves NMOF stability and functionality. Despite being in the early stages of development, NMOFs show great promise as a novel platform for nanomedicine, with potential for further optimization in terms of biocompatibility and tissue specificity.Metal-organic frameworks (MOFs) have been scaled down to nanometer sizes, leading to the development of nanoscale metal-organic frameworks (NMOFs) for biomedical applications. NMOFs offer several advantages over conventional nanomedicines, including structural and chemical diversity, high loading capacity, and intrinsic biodegradability. They can be synthesized under relatively mild conditions and tuned to optimize particle properties. NMOFs can be loaded with active agents through two main strategies: incorporation during synthesis or post-synthesis loading. NMOFs have been explored as MRI contrast agents due to their ability to carry large amounts of paramagnetic metal ions, with Gd3+, Mn2+, and Fe3+-containing NMOFs showing excellent efficacy. They have also been used for optical imaging and X-ray CT imaging by incorporating luminescent or high-Z element building blocks. In drug delivery, NMOFs have been used to encapsulate anticancer drugs, such as cisplatin prodrugs, with sustained release and comparable efficacy to free drugs. Surface modification with silica coatings or organic polymers improves NMOF stability and functionality. Despite being in the early stages of development, NMOFs show great promise as a novel platform for nanomedicine, with potential for further optimization in terms of biocompatibility and tissue specificity.