High purity tetragonal BaTiO3 powders consisted of uniform particles of ca. 150 nm in diameter were synthesized by a composite-hydroxide-mediated approach at 240 degrees C using a novel hydrothermal reaction apparatus with a rolling system. The product showed sinterability superior to the commercial powder, i.e., it could be sintered to full theoretical density at 1200 and 1100 degrees C without an additive and with 0.3 wt% of Li2CO3-0.04 wt% of V2O5 mixed sintering aid, respectively. The sintered body of the product also showed piezoelectric properties superior to the commercial one. (C) 2010 Elsevier Ltd. All rights reserved.