Chromium selenide (CrSe) crystalline thin film has been produced via chemical bath deposition on substrates (commercial glass). Transmittance, absorption, optical band gap and refractive index of the films have been examined by UV/VIS. Spectrum. Structural properties have been examined and XRD hexagonal form has been observed. The structural and optical properties of CrSe thin films, produced at different pH levels were analyzed; SEM and EDX analysis have been performed for surface analysis and elemental ratio of the films. It has been found that some properties of the films have been changed with pH and the changes of these properties with respect to pH have been investigated. Tested pH values were between 8 and 11. The optical band gap has been varied between 3.80 and 3.92 eV and film thickness has been changed from 76 nm to 126 nm for tested pH levels. Absorbance values were found to be 0.053, 0.018, 0.012 and 0.069 for pH values of 11, 10, 9 and 8, respectively (550 nm wavelength). The refractive index of CrSe thin films have been changed with film thickness, found as 2.27, 2.24, 2.25 and 2.26.