Pb[(Zr_1/2Ti_1/2)_0.7(Zn_1/3Nb_2/3)_0.3]O₃ (PZT-30PZN) powder was prepared using the columbite precursor method. The phase development of calcined powder precursors was analyzed by X-ray diffraction. Dielectric and ferroelectric properties of the as-sintered and annealed samples were measured and correlated with microstructure. The morphology evolution was determined by a scanning electron microscopy (SEM) technique. The as-sintered ceramic exhibited weak relaxor-ferroelectric behavior, with a relatively low dielectric constant maximum measured at 1 kHz (K _m@1 kHz) of 14 000. Annealing resulted in a transition to normal–ferroelectric-like behavior, a shift in the dielectric maximum temperature from 310°C to 300°C, and a dramatic increase of K _m@1 kHz to a maximum value of 25 100 for the longer anneal. After thermal annealing at 900°C for 1 week a strong enhancement of remanent polarization (P _r ) was observed.