Single crystals of a semi-organic nonlinear optical (NLO) material, l-proline cadmium chloride monohydrate (l-PCCM), were grown by the slow evaporation and slow cooling method. The synthesized material was purified by repeated recrystallization. The grown crystals were transparent and had dimensions 16 × 8 × 5 mm3; they were characterized by single-crystal XRD, FT−IR, CHN analysis, density, melting point measurements, and UV−vis−NIR techniques. The SHG efficiency of l-PCCM is twice that of potassium dihydrogen phosphate (KDP).