Abstract: Objective: This study is a fundamental step towards achieving the optimized conditions needed to improve efficiencies of NiSe-based solar cell devices. Methodology: Thin films of NiSe (nickel selenide) were deposited at different concentrations (0.10-1.00 M) using the chemical bath deposition technique. The other deposition variables were kept constant. The films were characterized using optical spectroscopy to investigate the absorbance, transmittance and reflectance versus wavelength measurements. Results: The results show that the absorbance of the films were very low (<1%), indicating that the films were highly transmitting (>50%). The optical absorption coefficient were >104 cm–1, the energy bandgap was direct with values in the range 1.60-2.0 eV. Conclusion: These values strongly suggest the use of these films in device fabrication especially in solar cell devices.