A novel, facile modified hydrothermal reaction route to nearly free-standing lead zirconate titanate (PZT) particles is presented. Simple mixing of fresh coprecipitates and mineralizer KOH followed by a hydrothermal treatment at 200 °C, produced PZT nanoparticles. Mineralizer KOH plays an important role in the size control and phase formation of PZT nanoparticles. According to TEM, HRTEM, SEAD, and XRD investigations, a KOH concentration of 4 mol L−1 results in highly crystalline and nearly free-standing PZT nanopartilces in the size regime of about 4 nm. Lower concentration of KOH leads to cubic PZT particle with several micrometers. However, higher concentration should results in amorphous PZT powders and of crystal nuclei with nice thermal stability in the temperature range of room temperature to 1000 °C. This simple low-cost approach should promise us a future large-scale synthesis of free-standing PZT nanoparticles for many important applications in nanotechnology and for the fundamental studies of n...