The nonlinear optical single crystals of glycine sodium nitrate were grown by the slow evaporation method. XRD confirmed monoclinic structure. Thermal stability and melting point (225 degrees C) were investigated. The dielectric behaviour of the crystals in the frequency range 20 Hz-2 MHz at different temperatures is reported in which a ferroelectric to paraelectric phase transition at T-c = 56 degrees C is observed. The activation energies of GSN were found to be 3.615 eV, 0.593 eV and 0.0733 eV in three temperature regions of conductivity plot due to a hopping conduction mechanism. The crystal has shown high piezoelectric charge coefficient (d(33)) of 16 pC/N which is nearly double of observed value for gamma-glycine single crystal. The spontaneous polarization P-s at room temperature was found to be 1.489 mu C/cm(2) at applied maximum field of 26 kV/cm (1.194 mu C/cm(2) at 12 kV/cm) and the pyroelectric coefficient was determined to be 400 mu C/m(2)/degrees C. High value of squareness parameter (1.93) makes the GSN crystal suitable for switching applications. Detailed investigations of Ferro-/Piezoelectricity were observed for the first time in glycine sodium nitrate crystals which was found to preserve the ferroelectricity even after applying an electric field much higher than the saturation electric field (12-26 kV/cm). Application of GSN crystals as sensor, high power switch gears and storage memories has been established. (C) 2013 Elsevier B.V. All rights reserved.