The effect of tungsten over Mo-V-O-based catalysts is evaluated. Alumina-supported Mo-V-W-O samples were prepared with different overall metal loading coverages, considering several relative metal atomic ratios; a bulk sample was also synthesized. The catalysts were characterized with BET, XRD, XPS and UV-vis. Mechanistic aspects of the light hydrocarbon oxidation were studied by the operando Raman-GC approach. Different surface structures were found and the better propylene yields were achieved when Mo-W and V-W were predominant structures. W incorporation to alumina-supported Mo-V catalysts yields better performance for propane ODH. (c) 2006 Elsevier B.V. All rights reserved.