A nanocrystalline La 2Mo 2O 9 powder was synthesized via the pyrolysis of polyacrylate salt precursor prepared by an in situ polymerization of the metal salts and acrylic acid. The pyrolysis behavior of the polymeric precursor was studied by thermal (TG/DTA) analysis. The obtained product was characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM) analysis. The results revealed that the average particle size is ∼25 nm for La 2Mo 2O 9 with good crystallinity. The synthesized nanocrystalline La 2Mo 2O 9 powder showed good sinterability and reached ∼99% of theoretical density when sintered at 800 °C for 4 h. The La 2Mo 2O 9 sample sintered at 800 °C, yield good microstructure with improved conductivity value of about 0.12 S/cm at 800 °C.