The ZnO nanorod-based hollow microspheres have been prepared via a simple hydrothermal reaction of [Zn(NH3)(4)](2+) with KBH4 at 140 degrees C for 8 h using Zn(CH3COO)(2) center dot 2H(2)O, ZnSO4 center dot 7H(2)O or Zn(NO3)(2) center dot 6H(2)O as the Zn source. The hollow microspheres with the diameters of 2 - 4 mu m are constructed from ZnO nanorods with the hexagonal wurtzite structure and diameter of about 100 nm. A possible mechanism was proposed to account for the formation of hollow ZnO nanorod-based microspheres. Phonon replicas associated with 2-E-2 phonon are observed in the PL spectrum from the ZnO superstructures. (C) 2008 Elsevier B.V. All rights reserved.