Mn-doped KTaO3 samples were prepared by the solid-state method. From the analysis of A-and B-site substitution characteristics, we determined the solid solubility limits for both doping mechanisms, the influence on unit cell parameters, the phase relations, and the sintering characteristics. The sintered samples were used for the analysis of microwave dielectric properties. From the temperature and frequency dependence of permittivity and dielectric loss as a function of Mn content in KTaO3 the behavior of polar regions, induced by the doping, was estimated.