We developed an aqueous solution process to synthesize crystalline ZnO particles and control their morphology. ZnO crystals were prepared in an aqueous solution containing zinc acetate and ammonia at 50 degrees C with no additional phase. ZnO particles having long hexagonal cylinder, short hexagonal cylinder, rounded hexagonal cylinder, rounded ellipse, pointed ellipse or multi-needle shapes were homogeneously nucleated and precipitated in solution. Crystal growth and preferential growth faces were controlled by solution conditions. Morphological control techniques in this system will contribute to the development of solution chemistry for inorganic materials and future oxide devices. (C) 2007 Elsevier Ltd. All rights reserved.