Hydrogen is regarded as a promising energy carrier to substitute fossil fuels. However, storing hydrogen with high density remains a challenge. NaBH4 is a potential hydrogen storage material due to its high gravimetric hydrogen density (10.8 mass%), but the hydrogen kinetic and thermodynamic properties of NaBH4 are poor against the application needs. Nanosizing is an effective strategy to improve the hydrogen properties of NaBH4. In this context, we report on the direct synthesis of NaBH4 nanoparticles (~6–260 nm) from the NaOCH3 precursor. The hydrogen desorption properties of such nanoparticles are reported as well as experimental conditions that lead to the synthesis of (Na2B12H12) free NaBH4 nanoparticles.