We have demonstrated the crystalline ZnO-Al2O3 core-shell nanowire structure by atomic layer deposition (ALD) at a temperature 100 degrees C. The core-shell structure could have potential applications in the fabrication of ZnO field effect transistor. After dissolving the ZnO core, shape defined, rigid and robust crystalline Al2O3 shelled nanostructures have been fabricated. Nanowire ZnO nanostructures have been replicated by alumina shell. This is one of the most effective techniques for producing core-shell or shell/hollowed nanostructures of any desired objects. The Al2O3 shelled nanostructures could have potential applications as space confined nanoreactors, drug delivery, nanofluidic channels and optical transmitting. (C) 2008 Elsevier B.V. All rights reserved.