Single crystals of bis(benzene-1,2-dicarboxylato)bis(thiourea)zinc (ZTP) were successfully grown by slow evaporation solution growth technique and characterized by means of single-crystal X-ray diffraction analysis. The compound C18H18N4O8S2Zn crystallizes at monoclinic system with centrosymmetric space group C2/c and its structure is built up from tetrahedral (ZnO2S2) linked to each other through the phthalate and thiourea groups. The good crystallinity of the as-synthesized specimen is confirmed by the powder X-ray diffraction pattern. The band gap energy is estimated using diffuse reflectance data by the application of Kubelka - Munk algorithm. Photoluminescence exhibits fluorescent emission of ZTP in the solid state at room temperature. The scanning electron microscopy (SEM) images reveal the surface morphology and the presence of Zn(II) in the specimen is further confirmed by the energy dispersive X-ray spectroscopy. Theoretical calculations were performed using density functional theory (DFT) method to derive the optimized geometry, dipole moment and polarizability. [GRAPHICS] .