In this work, the effect of gamma and CO2 laser radiations on the optical properties of 2% (wt/v) concentration of pure chitosan has been investigated. The optical properties (absorption, transmission, molar absorption coefficient and refractive index) of all prepared samples of chitosan solution, before and after gamma and CO2 laser irradiated, were studied in the wavelength range (200-1100) nm for a gamma dose rate of 0.1 mR h -1 , and CO2 laser power of 5W. The time of irradiation was five and ten days for gamma ray and 5s and 10s for laser. It has been found that there is an increase in the absorption of all samples irradiated with both types of radiation gamma and CO2 laser. The transmission of all samples was decreased. The refractive index of all samples was decreased in the wavelength range (200-400) nm and then increased in the wavelength range (400-1100) nm for both types of radiations. It has also been found that the values of molar absorption coefficient for all irradiated samples were increased.