The effect of high-energy ball mechanochemical activation on microstructure and electrical properties of PZT from commercial PZT powder has been studied in this paper. The mechanochemical treatment destroys the large particles and refines the grains of the commercial PZT powder. The milled PZT powder can be fully sintered at a very low temperature of 950 A degrees C, which is much lower than that of the pristine powder. More importantly, the grain growth is effectively prevented, while electrical properties of the final PZT ceramics are well maintained, due to the significant reduction in sintering temperature. It is believed that this technique can be readily extended to other materials.