Organic nonlinear optical single crystal of 4-methylpyridinium 2-carboxy-6-nitrobenzoate (4MPCNB) was grown from aqueous solution by the slow evaporation solution growth technique at ambient temperature. HRXRD analysis reveals that the monoclinic 4MPCNB crystal shows good crystalline perfection. The molecular structure information, transmittance and emission properties of grown crystal were elucidated by FTIR, UV–visible and photoluminescence studies. The dielectric constant and dielectric loss of the crystal were estimated as a function of frequency at various temperatures. The laser damage threshold was measured by using Nd:YAG laser source, and these results were mutually related with specific heat capacity of the grown crystal. Third-order nonlinear optical susceptibility was measured by Z-scan technique. © 2018, The Optical Society of India.