The 8-hydroxyquinolinium 3,5-clinitrobenzoate crystals were grown using slow evaporation solution technique. The structure was confirmed by single crystal X-ray diffraction and nuclear magnetic resonance analyses. The Fourier transform infrared and Raman spectral analyses were carried out to identify the various functional groups present in the title crystal. The optical properties were investigated by means of ultraviolet-visible spectroscopy and Kurtz-Perry powder method. Thermal Properties were characterized by thermogravimetry, differential thermal analysis and differential scanning calorimetry. The mechanical strength of the crystal was investigated by Vickers microhardness tester. Additionally, first-order hyperpolarizability, nuclear magnetic resonance, molecular orbitals, electronic excitation and electrostatic potential were calculated theoretically by density functional theory using Gaussian 03 program package. (C) 2014 Elsevier B.V. All rights reserved.