gamma-AlOOH architectures with hollow and self-encapsulated structures have been selectively synthesized by a facile one-step wet-chemical route. It is interesting to note that the condensed cores could be self-encapsulated into the hollow shells, and that the hollow shells were constructed with gamma-AlOOH nano-flakelets and showed urchin-like morphologies. gamma-Al2O3 hollow and self-encapsulated architectures have been synthesized by thermal decomposition method using the as-synthesized gamma-AlOOH as precursors, and the morphologies and microstructures of gamma-AlOOH have sustained very well. The surface area of gamma-Al2O3 hollow microspheres was calculated to be 116.9 m(2) g(-1). (c) 2008 Elsevier B.V. All rights reserved.