Organic nonlinear optical crystal, 8-hydroxyquinolinium hydrogen maleate (8-HQM) with a dimension of 30 x 4 x 4 mm(3) was grown by the slow evaporation solution growth technique. The cell parameters of grown crystal were confirmed by single crystal X-ray diffraction analysis and it belongs to the noncentrosymmetric space group P2(1)2(1)2(1). The crystalline perfection of 8-HQM crystal was examined by high resolution X-ray diffraction studies. UV-vis transmittance studies confirm the optical transparency window in the (480-900 nm) region. The TGA/DTA thermal measurements reveal that 8-HQM is thermally stable up to 160 degrees C. The laser damage threshold value of 8-HQM crystal was estimated to be 1.2 GW/cm(2) using a Nd:YAG laser. The relative second harmonic generation efficiency of 8-HQM crystal was found to be seven times greater than that of KDP. (C) 2013 Elsevier B.V. All rights reserved.