Lead zirconate titanate (PZT) nanopowders with high sintering activity were synthesized from economical raw materials by a simple water-based sol–gel method. Citric acid was used to complex with the metal cations, and the effect of the molar ratio of citric acid to metal cation (C:M) was investigated. The decomposition of the dried gel and the phase formation process of the PZT powders were investigated using thermal analysis, X-ray diffraction, and Fourier transform infrared spectroscopic techniques. The average particle size of the PZT powders was 13 nm after calcination at 600°C for 3 h, as determined by transmission electron microscope. The nanopowders prepared could be sintered at a temperature as low as 900°C, and dense PZT ceramics of pure perovskite phase were obtained. The electric properties of the ceramics derived from nanopowders were compared with those prepared by the solid-state method. The results show that due to larger c/a ratio and small grain size, the electric properties are enhanced.