In this study, we have developed a simple, versatile, and rapid solvothermal process for the preparation of sodium metal fluoride (NaxMFy) nanopowders (NaCoF3, NaMnF3, and Na3FeF6) using a microwave digestion system. Microwave heating significantly reduces the reaction time compared to conventional heating methods. The NaxMFy nanopowders have cluster structures consisting of small primary nanoparticles, thus resulting in a large surface area of >60 m(2) g(-1). The effect of an essential additive is also investigated to confirm the optimal conditions for obtaining large-surface-area NaxMFy nanopowders without impurities. We expect that this study will promote further research into the development and application of various nanostructured NaxMFy materials.