Single crystals of Allylthiourea Cadmium Chloride (ATCC), organometallic nonlinear optical material have been grown from aqueous solution by slow evaporation method. The structure of the grown single crystals have confirmed by single crystal XRD and CHN whereas the morphology has been studied using SEM. The optical transparency and optical band gap of the grown crystal are determined using UV-Vis spectroscopy. The third order nonlinear optical property of the ATCC is studied using Z-scan technique. The dielectric properties and ac conductivity of the crystal as a function of frequency and temperature are also investigated.