In this paper, the effect of metal (Cu2+ and Mg2+) and aminoacid (glycine) dopants on the growth and properties of L-lysine monohydrochloride dihydrate single crystals is reported. The grown pure and doped L-LMHCl single crystals were confirmed by single crystal X-ray diffraction (XRD) and FT-IR spectral analysis. High-resolution X-ray diffraction (HRXRD) and etching studies were carried out in order to analyze the crystalline perfection and surface morphology of the grown pure and doped crystals, respectively. The mechanical properties, dielectric behaviour, optical transmittance and second harmonic generation efficiency have been studied for pure and doped L-LMHCl single crystals. (C) 2010 Elsevier B.V. All rights reserved.