A new organic nonlinear optical material L-tartaric acid-nicotinamide (LTN) has been synthesized and single crystals have been grown from its aqueous solution by slow evaporation method. The solubility of the material was measured at various temperatures in de-ionized water. Single crystal X-ray diffraction analysis reveals that the crystal belongs to monoclinic system with the space group P2(1). The mode of vibration of different molecular groups present in LTN was identified by FTIR spectral analysis. The UV-vis-NIR spectrum of LTN shows less optical absorption and good transmittance in the entire visible region enabling its use in optical application. Second harmonic generation (SHG) was confirmed by the Kurtz powder method. Thermo gravimetric and differential scanning calorimetric (DSC) studies were carried out to determine the thermal properties of the grown crystal. The electrical measurement was made in the frequency range 100 Hz-1 MHz and in the temperature range 313-403 K along b-direction of the grown crystal. The electrical conductivity and dielectric studies were also carried out and reported for the first time. (C) 2010 Elsevier B.V. All rights reserved.