This paper deals with the structural and optical properties of virgin (i.e., as-evaporated) and annealed (i.e., thermally relaxed) amorphous As40S60−xSex films (x=0, 20, 30, 40 and 60 at.%), which were prepared by vacuum evaporation. Structural properties have been inferred from the X-ray diffraction patterns and the Raman spectra of the thin-film samples. The decrease in the intensity of the first sharp diffraction peak after annealing suggests that the thermal relaxation is connected with a decrease in the free volume leading to an increase of the structural compactness. A significant decrease in film thickness has been invariably found after annealing in all cases, which supports this conclusion. Changes found in the Raman spectra of the film samples after annealing indicate a reduction in the concentration of homopolar bonds, which are present in the molecular fragments embedded in the amorphous matrix. Thus, the thermodynamic state of the system is shifted towards equilibrium as a result of thermally induced polymerization (homogenization). These structural changes also resulted in significant changes in both the refractive index and optical band gap, Egopt.