Here we report the first aqueous solution-based synthesis route to lanthanum tungstate nanopowders (La28−xW4+xO54+3x/2). Lanthanum tungstate-based materials have high proton conductivity at elevated temperatures making them interesting for several energy technology applications. The La28−xW4+xO54+3x/2 powders prepared by developing a new aqueous precursor solution have a narrow particle size distribution with an average grain size of 100 nm. Different pre-consolidation conditions were studied to enhance powder performance. Dense, single phase materials with homogeneous microstructures with grain size ~4 μm were obtained using sintering temperatures at 1400°C in air. Changing the La/W-ratio from 5.6 to 5.4 did not affect the densification rate, however, a slight increase in grain growth rate was observed.