A new sol-gel method has been developed to synthesize high surface area gamma-aluminium oxide. The preparation was carried out at ambient temperature using a special reactor which allowed the dosing of gaseous water for the hydrolysis of aluminium alcoxide. Aluminium tri-sec-butoxide was used as precursor and acetone as solvent, since this mixture leads to a stable lyogel. After drying and pyrolysis a high surface area gamma-aluminium oxide xerogel was formed. The effect of heating on the morphology and structure was examined by nitrogen sorption (BET and pore size distribution), SEM, XRD and Al-27 MAS NMR. The results indicate that the xerogel is a highly stable material at elevated temperatures. Moreover, the high surface area xerogel exhibits an enlarged amount of acid sites which leads to an enhanced catalytic activity for example in the propene oxidation.