Ternary chalcogenide of copper and indium (CuIn5S8) thin films were grown by thermal evaporation method using GLancing Angle Deposition (GLAD) technique. The samples were prepared under different incident angles (alpha= 0 degrees, 40 degrees, 60 degrees and 85 degrees measured from the normal to the substrate surface) with a substrate rotation of 2 rpm. X-ray diffraction, scanning electron microscopy, and ultraviolet-visible-infrared spectra are employed to characterize the microstructure and optical properties of the CuIn5S8 thin films deposited by this technique. Under the GLAD conditions, we demonstrate that with substrate rotation, the columns were grown vertically due to the shadowing symmetry. The optical constants of the deposited films were determined from the analysis of transmission and reflection data. The results show that the refractive index and the thickness were decreased as alpha rises from 0 degrees to 85 degrees while the porosity and the Urbach energy were increased with increasing of the incident angle. The minimum refractive index is found to be 2.03 for the helical CuIn5S8 film deposited at an angle of 85 degrees and the Urbach energy was found to increase from 0.29 to 0.5 eV as alpha rises from 0 degrees to 85 degrees. Such changes of the optical behaviors are correlated with changes of the microstructure, especially a porous architecture which is favored for high incident angle. These properties exhibit potential for use in applications such as photonic crystals, graded index optical filters, and birefrigent omnidirectional reflectors. (C) 2015 Elsevier B.V. All rights reserved.