Thin films of vanadium oxides for ethanol sensor applications were been prepared by means of rf reactive sputtering from a vanadium pentoxide target in an Ar–O2 atmosphere. Films with the best sensitivity and selectivity were obtained with 15% oxygen at a working temperature between 280 and 300 °C. These films show a very low sensitivity to CO, CO2, and CH4 and total insensivity to NH3.