Lithium paranitrophenolate trihydrate (NPLi . 3H(2)O) is a new semiorganic nonlinear optical crystal. It has a d(eff) of about 2 times that of Lithium niobate. Large single crystals of size 16 x 9 x 6 mm(3) are obtained by isothermal solvent evaporation and the grown crystals are characterized using single crystal X-ray diffractometry (XRD), Fourier transform infra-red (FTIR), DRS-UV and solubility measurements. XRD analysis confirms the molecular formula and structure of the crystal. The DRS-UV spectrum shows good optical transparency in the entire visible region. The SHG efficiency of the crystal is measured by Kurtz's powder method using Nd-YAG Laser. (C) 2003 Elsevier B.V. All rights reserved.