Single crystals of Sb2Te3 doped with CdS were prepared by a modified Bridgman method from the elements Sb and Te of 5N purity and the CdS compound of 4.5N purity. Samples were characterized by X-ray diffraction and by measurement of reflectance in the plasma resonance frequency region at room temperature. Furthermore, we made measurements of temperature dependence of the electrical resistivity, Hall and Seebeck coefficients, and thermal conductivity in the temperature range of 4.2–300K. In the process of crystal growth, CdS dissociated and it was assumed that the Cd-atoms formed substitutional defects in the Sb-sublattice (CdSb′) while the S-atoms formed substitutional defects in the Te-sublattice (STe(−δ)).