L-prolinium picrate (C5H10NO2)(+)center dot(C6H2N3O7)(-), an organic nonlinear optical (NLO) material possessing a large second harmonic generation (SHG) efficiency (74 times higher than that of the standard KDP) was grown by slow evaporation method. The identity of the crystals was confirmed by using single-crystal X-ray diffraction. The crystalline perfection was studied by multicrystal X-ray diffractometer. Fourier transform infrared (FTIR) spectroscopic studies, optical behavior such as UV-visible-NIR absorption and SHG conversion efficiency were investigated to explore the NLO characteristics of the above material. The structural features of the material leading to the large SHG efficiency are discussed. Microhardness measurements and dielectric studies of the compound were also carried out. (C) 2008 Elsevier B.V. All rights reserved.