In this work, we report synthesis of ZnO nanocolumns with non-uniform side faces and different cross-sections. The nanocolumns were characterized by scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, and photoluminescence. All the nanocolumns grow along [0 0 0 1] direction, but different side surfaces can be observed in the top region of the nanocolumns. Three different morphologies found in the top region likely represent different growth stages of the nanocolumns. The growth mechanism of the nanocolumns is discussed. (c) 2005 Elsevier B.V. All rights reserved.