Abstract Alumina-zirconia and alumina-titania mixed oxides were prepared by coprecipitation of their corresponding chlorides. Samples were synthezised at several concentrations, dried and calcined at temperatures between 400°C and 800°C. All dried samples showed the bayerite structure, which upon calcination became first amorphous and later Al2O3. Anatase was observed only on the high content, high calcination temperature sample, but no crystalline phase of zirconia was detected. Surface areas of mixed oxides were higher than for alumina single oxide, and decreased with temperature. Carbon tetrachloride adsorption increased with TiO2 content, but the opposite effect was observed on alumina-zirconia samples.