The paper is focused on the possibilities of selective wet etching of optically and thermally crystallized/amorphous Ag-doped chalcogenide thin films, namely Ag x (As 0.33 S 0.67 ) 100− x and Ag x (As 0.33 S 0.335 Se 0.335 ) 100− x . The selective etching of optically(thermally) crystallized Ag x (As 0.33 S 0.67 ) 100− x and thermally crystallized Ag x (As 0.33 S 0.335 Se 0.335 ) 100− x thin films in water solution of NaCN is presented. The good surface quality is an important and crucial parameter for optical elements fabrication (e.g. grids, waveguides, etc.) especially in nanometer dimensions. The selective etching of undoped and Ag optically doped region was also carried out to observe surface roughness of doped region before and after selective etching. Characterization of the structure and surface of studied films by Raman spectroscopy, X-ray diffraction, AFM and SEM methods has been done and potential application suggested.