Single crystals of 1H-Imidazolinium Hydrogen L-tartrate (ImiLT) were grown by slow evaporation solution growth technique at ambient temperature in different solvents. The grown crystals were characterized by single-crystal XRD using MoK alpha (lambda = 0.71073 angstrom) radiation and the lattice parameters have been obtained. The Fourier transform infrared spectrum of 1H-Imidazolinium Hydrogen L-tartrate reveals the presence of carboxyl functional groups in the compound. The dielectric behaviour of ImiLT crystals was studied at different frequencies and temperatures. The optical transparency window in the UV-VIS region is found to be good for nonlinear optical applications. Thermogravimetric and Differential thermal analyses reveal that the compound decomposes beyond 204 degrees C. The theoretical factor group analysis predicts 138 internal modes of vibration and optical modes in the grown title compound. The SHG behaviour of the title Compound was demonstrated using Q-switched Nd:YAG laser. (C) 2009 Elsevier B.V. All rights reserved.