Preparation of catalytically important TiO2-Al2O3, TiO2-SiO2, TiO2-ZrO2, TiO2-SiO2-ZrO2 and SiO2-ZrO2 mixed oxides by coprecipitation method using urea as hydrolysing agent is described. These mixed oxides are X-ray amorphous and exhibit high N(2)BET surface areas.