In this study, Cu2NiSnS4 (CNTS) thin films were deposited on glass substrates at different temperatures of 250, 300, 350 400, and 450 ˚C using the chemical pyrolysis technique. The aim of this research was to study the effect of the substrate temperature on the properties of the films. The structural properties of the films were obtained by X-ray diffraction, Raman spectroscopy, and Field Emission Scanning Electron Microscopy (FESEM); the optical properties were determined by the UV-Vis spectroscopy; and the electrical properties were obtained by observing the Hall Effect. The XRD results showed that the CNTS films had a cubic crystalline structure with (111) being the preferred and most common orientation plane. Raman spectroscopy results showed a distinct peak at 336 cm-1 , which indicated a CNTS quaternary compound. The FESEM results demonstrated the presence of nanoparticles with various shapes and sizes. The optical energy band gap was proven to have a value of 1.57-1.82 eV, for the allowed direct transition, and a high absorption coefficient (≥104 cm-1 ) in the visible spectrum region, thereby indicating the potential application of these thin films in solar cells. The Hall Effect measurement on the CNTS thin films indicated a p-type of conductivity for all films, with the highest charge carrier density and mobility occurring at 350C, which makes them ideal for use in photovoltaic applications.