Branched Zn-doped SnO2 nanorod clusters with tunable size and aspect ratios were prepared by a facile solvothermal process. The introduction of a small quantity of Zn2+ proved to play an important role in directing the anisotropic growth of SnO2 nanocrystals. The as-synthesized products exhibit tetragonal rutile structure and many lattice defects exist in the products. The possible growth mechanism has been proposed. These Zn-doped SnO2 nanorods exhibited unique Raman spectrum in contrast with the undoped SnO2 nanostructures. These Zn-doped SnO2 nanorods showed good sensitivities to ethanol gas, acetone gas, and benzene gas. (C) 2007 Elsevier B.V. All rights reserved.