Uniform hexagonal Mg(OH)(2) flake-like nanostructures were successfully prepared by a simple low-temperature hydrothermal reaction between Mg(NO3)(2) and hydrazine hydrate without any further additives. X-ray diffraction (XRD), scanning electron microscopy and transmission electron microscopy were used to characterize the product. It revealed that it was pure Mg(OH)(2) with uniform, hexagonal and flake-like morphology. In-situ XRD investigation as well as DSC analysis showed that the Mg(OH)2 nano-flake was stable at 330 degrees C and decomposed to its oxide counterpart at about 370 degrees C. All these characteristics showed that the Mg(OH)(2). nano-flake have promising application as a flame retardant. (C) 2008 Elsevier B.V. All rights reserved.