ZnWO4 rods were prepared using a ligand-assisted hydrothermal method with ZnCl2 and Na2WO4 in the presence of various amines as ligands for zinc ions. The choice of ligand was found to play an important role in the formation of ZnWO4 rods. The aspect ratio of the ZnWO4 rods increased with increasing ligand strength. XRD and HRTEM confirmed that the ZnWO4 rods grow along the [1 0 0] direction. The photochemical activities of the ZnWO4 rods for the decomposition of Rhodamine 6G were examined. The photocatalytic activity was found to depend on the aspect ratio of the ZnWO4 rods. (C) 2010 Elsevier Ltd. All rights reserved.