A facile modified hydrothermal approach has been exploited to rationally synthesize perovskite-structured BaZrO3 microcrystals with the shapes of truncated rhombic dodecahedron and sphere. The polarity variation by ethanol introduction to the solutions plays a significant role in determining the geometric morphology of the final products. The BaZrO3 microcrystals can serve as host materials for rare earth photoluminescence, and shape-dependent luminescence properties of an Eu-doped material has been observed. Controlling the size and shape of perovskite oxides is of great importance both in basic and applied science due to their strong structure-dependent physical properties. (C) 2004 Elsevier B.V. All rights reserved.