We report the synthesis of potassium tungstate (K2W3O10) micro-walls by a simple method of thermal evaporation. Using tungsten powder, tungsten oxide powder and potassium iodide as the source materials and tungsten plate as the substrate, K2W3O10 micro-walls with thicknesses ranging from 400 nm to 2 pm, lengths up to hundreds of micrometers and heights up to tens of micrometers are obtained on a large scale. The possible mechanism for the formation of these tungstate micro-walls is discussed. (c) 2006 Elsevier B.V. All rights reserved.