Ferroelectric layered-perovskite BaBi2Ta2O9 has been successfully prepared through a novel process using BiTaO4 as a precursor. Heating the mixtures of BiTaO4 and BaCO3 at 900 °C without soaking results in the complete formation of the monophasic powder. In contrast, the conventional solid-state reaction requires soaking at 900 °C for 2 h to obtain the pure compound. Such prolonged heat treatment causes unfavorable growth of particles. In the new process, the formation of BaBi2Ta2O9 is markedly accelerated due to the suppression of the formation of a stable intermediate Ba5Ta4O15. In addition, this process yields submicron BaBi2Ta2O9 powder with significantly improved sinterability. Sintering at 1000 °C affords well-densified ceramics. On the other hand, heating at temperatures greater than 1100 °C causes BaBi2Ta2O9 to thermally decompose and form Bi2O3 and rod-like BaTa2O6. The formation of these rod-like grains results in the expansion of the matrix, thereby reducing the density.