The transmittance spectra of amorphous As2S3 films prepared by two different techniques, namely spin coating and quenched from the melt were investigated. All measurements were done at room temperature in the energy range from 1.2 to 3.8 eV. The spin casted material was prepared by dissolving powdered stoichiometric arsenic trisulfide in amines and amides, the resulting solution spinned on an oxide glass substrate and baked to remove the volatiles. A typical resulting film was a few micrometers thick and microstructure free as characterized under an optical microscope. The quenched material was prepared by melting a stoichiometric mixture of the reactants in an evacuated and sealed ampoule and alloying at 1100°K for 15 hrs. The melt was subsequently quenched in air to obtain vitreous materials. The transmittance spectra of both types of samples was measured and from the spectra the refractive index dispersion, film thickness and absorption coefficient were obtained. A considerable difference between the optical constants of the spin casted samples and thermally evaporated ones was found. This was attributed to the incorporation of carbon and hydrogen in the amine salt alkyl group formed when dissolving the chalcogenide material.