ZnO is a valuable material for display devices, for catalytic chemical reactors, and as sorbents for desulfurizaton because of its excellent chemical and thermal stability. In this work, we report the synthesis of flower-like ZnO structures using a continuous flow microreactor over an oxidized silicon substrate. A chemical solution that employed zinc acetate [Zn(CH3COO)(2)center dot 2H(2)O] and sodium hydroxide [NaOH] was used as precursors. The effects of water bath temperature, impinging time and concentration of NaOH on the growth of the flower-like structure have been investigated in this study. It was confirmed that the size of the fabricated flower-like structure was increased as the impinging time and the water bath temperature were increased. Various flower-like morphologies were observed according to the different concentration of NaOH. Scanning electron microscope (SEM) was used to study the morphologies of the synthesized flower-like ZnO structures. X-ray diffraction (XRD) was used to characterize the crystal structures of the ZnO crystallites as a function of the concentration of sodium hydroxide. (C) 2007 Elsevier B.V. All rights reserved.