Pure MgMn2O4 spinel nanostructures were synthesized by the sol – gel method using stearic acid as a reducing and complexing agent. Structural characterization performed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM) with energy dispersive spectrometry(EDS) mapping, Diffuse reflectance spectroscopy (DRS), Vibrating sample magnetometer (VSM) and surface areaanalyses (Brauner – Emmett – Teller). In this work, the hydrogen storage capacity of MgMn2O4 nanostructures was studied by the chronopotentiometry (CP) technique for the first time. The discharge capacity of the Magnesiummanganese oxide in 1 mA current and after five cycles achieved 2000 mAh/g. Therefore, MgMn2O4 spinel nanostructures could be suitable materials for energy storage applications.