The leucite crystallization kinetics from a hydrothermally derived precursor seeded with nano-crystalline leucite was investigated by X-ray diffraction and non-isothermal differential thermal analysis. The nano-crystalline leucite was prepared by high-energy milling of high-purity leucite powder and the leucite precursor was prepared by the hydrothermal method of silica sol, aluminum nitrate, and potassium nitrate. After the seeds were introduced, the crystallization temperature of the precursor was lowered by 100 degrees C and the transition phase kalsilite did not appear during the crystallization process. When the seeded precursor was heat treated at 700 degrees C, a small amount of cubic leucite was stabilized to room temperature. The seeded precursor showed an exothermic peak between 800 degrees and 920 degrees C under different heating rates. The activation energy for the growth of leucite from the seeded precursor was 256(SD9) kJ/mol.