L-Lysine monohydrochloride dihydrate (LLMHCl), a semiorganic potential nonlinear optically active crystal possessing large hyperpolarizability and which belongs to noncentrosymmetry class has been grown and studied. The XRD analysis shows that it belongs to the auspicious symmetric space group P2(1) with two molecules in the asymmetric unit. FTIR and FT Raman of the title crystal have been studied at room temperature. The polarization light and oriented single crystals are used to assign the lines observed in the Raman spectra of the studied material. The vibrational spectral characterization has been carried out and interpreted in the light of crystal structure data and factor group analysis. The second harmonic generation (SHG) measurements have allowed identifying the C2 space group symmetry of the compound corroborating very good propensity for green emission. The optical and mechanical responses have been studied with respect to UV visible and Vickers microhardness measurements.