[en] Crystallographic properties of ZN x Cd 1-x S and CdSe 1-y S y polycrystalline thin films deposited by evaporation were studied through X-ray diffraction and photoluminescence measurements. From these studies, it was determined the effect of the chemical composition on the crystalline structure, lattice parameters and crystallographic quality of the samples. It was found that the samples of Zn x Cd 1-x S and CdSe 1-y S y grow in a texturized way and that the binary CdS and Cd Se compounds present a mixture of the cubic and hexagonal