Submicrometer lanthanum ortho-niobate (LaNbO4 (LN))-based powders have been prepared by spray pyrolysis of an aqueous solution containing stable La-EDTA and Nb-malic acid complexes. The powders had a particle size of similar to 0.1 mu m, a narrow particle size distribution, and high purity after calcination above 800 degrees C. The powders possessed excellent sintering properties resulting in > 98% dense materials at 1200 degrees C. The present route is shown to be excellent for the large-scale preparation of high-quality LaNbO4-based powders.