Oxidative dehydrogenation, ODH, of isobutane has been performed on chromia supported on SiO2, Al2O3, TiO2, ZrO2 and MgO. The potassium promoted (K/Cr = 0.1) catalysts have also been examined. The supported chromia has been found active in the ODH of isobutane at relatively low temperatures 200-400 degrees C, the total activity and selectivity to isobutene depending on the nature of the support and the potassium presence. The highest selectivities to isobutene (ca. 70% at 5% conversion) and the isobutene yields of ca. 9% have been obtained for CrOx/TiO2 and K-promoted CrOx/Al2O3 preparations.