Three series of vanadium-containing silica catalysts (2-7.6 wt% V) have been prepared by varying the synthesis method. In all cases, conversion values in the oxidative dehydrogenation of propane increase with the temperature, vanadium loading and reducibility. For impregnated and anchored catalysts, a relationship between the selectivity towards propene and the effective acidity, as determined in the dehydration of 2-propanol, can be established.