Structural, thermal, morphological and optical properties of ZnWO4 sample were investigated by X-ray diffraction, atomic force microscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy analyses (EDX) and spectroscopic ellipsometry (SE). Electrical properties of the ZnWO4 compound were studied using complex impedance spectroscopy in the frequency range 200 Hz–5 MHz and temperature range 484–593 K. Temperature dependence of d.c. and a.c. conductivity indicates that electrical conduction in the material is a thermally activated process. The objective of the present work is to investigate the thicknesses and optical constants of ZnWO4 sample prepared by hydrothermal process using SE by new amorphous dispersion formula in the spectral wavelength range of 200–2200 nm. The results of the optical constants were extracted from SE measurements for the ZnWO4 sample experimentally (EXP) and theoretically (FIT), showed an excellent agreement.