The known heterogeneous catalytic dehydration of ethanol on amorphous aluminium oxide samples was adopted as a measure of catalytic activity and selectivity. The aluminium oxide samples were prepared by hydrolysis of aluminium chloride using propylamine, as proton acceptor, in pure and mixed aqueous ethanolic and acetonic media, freeze dried and activated. The catalytic activity and selectivity of the samples was measured in the temperature range 623-698 K for various flow rates of ethanol. The apparent activation energies were calculated (53-78 kJ mol(-1)) and depended on the solvent used in the preparation of the aluminas. The effect of solvent medium on the activity and selectivity was discussed.