Nanocrystalline Mg 2 SnO 4 nanophosphor was synthesized by a facile sol-gel auto-combustion method calcined 800 • C for 1 h. The X-ray diffraction pattern showed that the nanopowder has a cubic inverse spinel polycrystalline structure with an average crystallite size of about 20 nm. The photoluminescence spectra were measured at 84−300 K, and the broad emission band was obtained in the wavelength range of 400−500 nm. Photoluminescence at 120 K showed the highest emission band centered around 414 nm. The thermoluminescence (TL) glow curve showed an increase in TL peak intensity with UV irradiation time due to the increasing number of inherent traps created by UV irradiation. The maximum TL intensity was found for 30 min UV exposure. Activation energies of the trapping centers were found between 0.39 eV and 0.48 eV. The frequency factor of the main glow-peak was also evaluated in the 3.03 × 10 6 -4.26 × 10 7 s −1 range for UV irradiated phosphor. The decrease in activation energy and frequency factor with increasing UV exposure time may attribute to the decrease in trap depth. The calculated trap parameters related to the glow peak show this phosphor may be useful in radiation dosimetry applications.