A layered zinc compound is afforded by the heating of zinc acetate dihydrate with mandelic acid in dibenzyl ether. Thermolysis of the layered compound results in the formation of hollow spheres constructed from plate-like ZnO nanocrystals (NCS) in high yield. Size-controlled hollow spheres with a 690 nm diameter (size variation = 6.0%) are obtained by thermal treatment at 300 degrees C for 15 h. In this reaction, the mandelate moiety plays important roles not only in morphology control of ZnO NCs but also for the formation of hollow structures constituted of ZnO nanoplates.