Today nonlinear optical organic materials are widely used for a variety of photonic technologies. Many NLO organic single crystals have been identified as potential candidates in optical and electro-optical devices. In this paper, we report the mechanical anisotropic hardness behaviour of the organic NLO molecular crystal methyl parahydroxybenzoate (MHB). MHB compound was synthesized and the crystals were grown by solution growth technique. Single crystal X-ray diffraction studies were carried out to determine the lattice parameters of the grown crystal and SHG measurements reveal SHG efficiency 15 times higher than Urea. MHB is an aromatic crystal with noncentrosymmetric structure, and exhibits anisotropy in mechanical behaviour. The Vickers microhardness studies were carried out on all the visible planes using Vickers microhardness tester and the microhardness owing to plastic deformation is discussed in terms of various slip systems. A suitable combination of acetone and methanol as etchant was identified for visualizing the slips.