The bis(guanidinium) 5-sulfosalicylate organ sulfur nonlinear optical single crystals, were grown by slow evaporation growth technique. The crystal system and the lattice cell parameters of the grown crystal were confirmed by single-crystal XRD. The morphology of grown crystal reveals the growth natures of the material. The chemical composition and functional groups in the grown crystal have been confirmed by FTIR spectral studies. Optical characterization shows that BG5SS has a broad transmission window range and the lower cut off wavelength found at 348 nm. The photoluminescence spectrum shows that BG5SSdisplays an extensive red luminescence emission at 660 nm in the solid state at room temperature. The calculated ‘n’ values of BG5SS are n1 = 1.14; n2= 0.955 corresponding to (0 1 1) and (0 0 1) planes respectively, and it comes under hard material category. Single shot surface laser damage threshold is determined to be 1.7 GW/ cm2 at 1064 nm laser radiation. Its SHG efficiency is about 0.16 times that of KDP. Keywords: evaporation growth technique, XRD, fluorescence spectral study SHG, micro hardness