Single crystals of tris(thiourea) zinc nitrate (Zn (NH2CSNH2)3)(NO3)2, abbreviated as TZNN, a organo metallic single crystal have been grown successfully by slow evaporation method. Crystal of dimensions 1.122 cm3 was harvested after a period of 45 days and is reported. X-ray diffraction analysis has been carried out to confirm orthorhombic system and etching studies for their growth orientation and perfection. The powder x-ray diffraction of the crystal recorded and the various planes of reflections are identified. The presence of functional group and the coordination of metal ions to thiourea were confirmed by FTIR analysis. The transmission spectrum reveals that the crystal has low UV cutoff of 302 nm and has a good transmittance in the entire visible region enabling its use in optical applications. The thermal behavior of the crystal has been investigated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA), which indicates that the material does not decompose before melting. Mechanical strength of the crystal has been analyzed using Vickers' micro-hardness test. Studies of dielectric properties like dielectric constant and dielectric loss as function of frequencies for varying temperatures in the range 303 - 433 K suggests these crystals are good candidates for electro optic modulators and frequency convertors.