A La(OH)(3) gel solvothermal process has been developed for the preparation of nanocrystalline lanthanide oxysulfide (La2O2S) in polar solvents at 300 degrees C through a reaction between a La(OH)(3) gel and K2S. X-ray powder diffraction (XRD) indicated that the product was hexagonal La2O2S with cell parameters a = 4.046 Angstrom and c = 6.951 Angstrom. Transmission electronic microscopy (TEM) showed that different morphology nanocrystallites were formed, including particles with diameters of about 10 nm and nanorods about 10 nm in diameter and 300 mn in length, depending on the solvent.