A new semiorganic non-linear optical thiosemicarbazide cadmium chloride monohydrate (TSCCCM) material has been synthesized. TSCCCM single-crystals were grown from aqueous solution by slow cooling and slow evaporation methods. Solubility of TSCCCM has been determined for various temperatures. The grown crystals were characterized by single-crystal X-ray diffraction (XRD) study, FTIR, SHG test, UV-vis, and EDAX analyses. Single-crystal XRD study has been carried out to identify the lattice parameters. FTIR studies confirm the functional groups present in the grown crystal. Optical transmission studies have confirmed that the grown crystals are highly transparent. The SHG conversion efficiency of TSCCCM crystals has found 14 times higher than the KDP crystal. In TSCCCM crystal structure, the planer pi-organic molecules combine harmonically with inorganic distorted polyhedrons. The chlorine atoms in TSCCCM must be involved in the coordinate polyhedra and have promoted the NLO property. (C) 2007 Published by Elsevier B.V.