Pure and 1, 1.5 and 2 mol% Mn2+ doped l-asparagine monohydrate (MLA) single crystals have been successfully grown from aqueous solutions by slow cooling method. Powder X-ray diffraction (XRD) patterns and FT-Raman spectra have been recorded to study the variation in the lattice parameters and functional groups with doping concentrations respectively. The influence of doping on optical transparency and laser damage threshold (LDT) was investigated for these crystals. Vickers microhardness tests in the load range of 10–100 g were carried out on (0 1 1) face of pure and doped MLA crystals and the different regions in the load variation of hardness have been discussed. Some hardness related parameters viz., crack length, fracture toughness and brittle index number of pure as well as doped single crystals have been studied.