A new nonlinear optical material glycine potassium sulphate (GPS) has been synthesized and optical quality crystals were grown from aqueous solution. This material has positive temperature coefficient revealed from the solubility studies. The grown crystals were characterized by employing several techniques such as single crystal and powder X-ray diffraction, thermo gravimetric analysis, FTIR and UV–vis–NIR spectra. The etching studies have been done on the (1 0 0) plane of the grown crystal. Preliminary measurements to find second harmonic generation efficiency of GPS has been carried out.