Ternary systems of Cd1−xMnxTe were synthesized by the direct fusion technique. Thin films of these compounds were prepared by an electron beam gun under a vacuum of 10−5 Torr. Structural properties of these compounds in thin film forms were investigated by X-ray diffraction. It was found that these materials crystallize in the zinc-blende form. The optical constants (absorption coefficient and band gap) of the thin films were determined by measuring their reflectance and transmittance in the wavelength region from 500 to 2500 nm. Analysis of the optical absorption spectra revealed the existence of one direct energy gap. The energy gap increases as the Mn concentration increases and with decreasing annealing temperatures. The electrical conductivity σ was measured at room temperature and was found to decrease with increasing Mn content.