<p><strong>Background: </strong>We report on synthesis, growth and characterization of Bis-thiourea L-lysine monohydrochloride (BTLM) crystal.</p><p><strong>Methods: </strong>Bis-thiourea L-lysine momohydrochloride (BTLM) crystal were grown by solution growth method in the molar ratio 1:1 at room temperature.</p><p><strong>Results: </strong>Transparent and defect free crystal of BTLM were harvested in the period of 40-45 days with dimension 7mm × 4mm × 2mm. Single crystal XRD analysis revealed that the crystal system belongs to Orthorhombic with cell parameters a= 14.41 Å, b= 5.89 Å and c= 15.52 Å. The sharp and well defined Bragg peaks observed in the powder XRD pattern confirm the crystalline nature of BTLM crystal. The presences of functional groups in the grown crystal BTLM were identified by FT-IR analysis. The fluorescence spectral study was carried out in the range of 280–500 nm. Second harmonic generation (SHG) of powdered BTLM sample was tested using Nd: YAG laser and is found to be 0.55 times that of potassium dihydrogen orthophosphate. The mechanical strength of the BTLM crystal was evaluated and it describes that the Vickers hardness number of BTLM is found to be increase with the applied load. The work hardening co-efficient (n) has been calculated from the slope of straight line between log P and log d. <sup> </sup>The dielectric study of BTLM was carried out as a function of frequency at different temperature.</p><p class="abstract"><strong>Conclusions: </strong>From the result we confirm that the BTLM crystals have good physicochemical properties. So, the grown BTLM crystal was suitable candidate for nonlinear optical applications.</p>