In the present work, the organic nonlinear material 3-methyl 4-nitropyridine 1-oxide (POM) has been synthesized from 3-picoline-N-oxide. Single crystals of POM have been grown by solvent evaporation method. Crystals of dimensions 1.1 x 0.8 x 0.4 cm(3) have been obtained by this technique. FT-NMR and FTIR techniques have confirmed its molecular and structural identification. The grown crystals have been characterized by single crystal X-ray diffraction method and their lattice parameters were determined. Optical transmittance spectrum shows transmittance of 55%. To investigate the mechanical properties of POM crystals, Vickers hardness studies were carried out in different planes and the hardness values have been determined. Second harmonic generation was observed by using Q-switched Nd:YAG laser confirming the NLO property. Laser damage threshold value has been determined using Q-switched Nd:YAG laser operating at 1064 nm with 20 ns pulses. (C) 2003 Elsevier B.V. All rights reserved.