Zinc guanidinium phosphate, a semi-organic single crystal, was grown successfully by a slow evaporation solution growth technique. The cell parameters of the grown crystal were confirmed using a powder X-ray diffraction study. The electrical property of the sample was analysed using dielectric and piezoelectric studies. The dielectric constant, dielectric loss and alternating-current conductivity were calculated for various frequencies and temperatures. The solid state parameters such as plasma energy, Penn gap energy, Fermi energy and electronic polarizability were calculated. The piezoelectric property of the title crystal was ascertained by determining its piezoelectric charge coefficient (d 33). The optical transmittance and energy gap of the grown crystal were examined using ultraviolet-visible-near-infrared spectral analysis. The title molecule was optimized and the frontier molecular orbital was performed using B3LYP/6-31 + G(2d,2p). The emission property of the titular compound was analysed using a photoluminescence study. The dominant colour emission of the grown crystal was found using CIE colour chromaticity coordinates. The nonlinear property of the titular compound was confirmed using a Kurtz-Perry powder technique. The above results illustrate that the title crystal is a potential candidate for light emitting and nonlinear applications. This work explains the dominant colour emitting behaviour and electrical properties such as dielectric and piezoelectric properties of the title crystal, which are reported for the first time.