Chemical bath deposition (CBD) technique was used for the synthesis of the Nickel Sulphide (NiS) thin films. The prepared NiS thin films were found to be polycrystalline and the crystals had hexagonal structure as revealed in the X-ray diffraction (XRD) analysis. The surface morphology of these films was studied by means of scanning electron microscopy (SEM). The optical properties of the NiS thin films were determined using UV-Visible absorption spectrum. The electrical studies were carried out at different frequencies and at different temperatures for the prepared NiS thin films. Further, electronic properties, such as valence electron plasma energy, average energy gap or Penn gap, Fermi energy and electronic polarizability of the NiS thin films were calculated. The AC electrical conductivity measurements revealed that the conduction depended on both the frequency and the temperature. Photoconductivity measurements were carried out to reveal the positive photoconductivity of the NiS thin films. © 2016, National Institute R and D of Materials Physics. All rights reserved.