Bismuth molybdenum titanium oxides, potential catalysts for the partial oxidation of olefins, were prepared via the sol-gel route. Either Bi(NO3)(3). 5H(2)O and (NH4)(6)Mo7O24. 4H(2)O, or BiCl3 and MoOCl4 were used as precursors together with Ti-isopropoxide. One sample was dried by semicontinuous extraction with supercritical CO2, affording an aerogel, the others were heated in vacuo resulting in xerogels. For comparison, two bismuth molybdenum oxides on a titania support, and a bismuth molybdate were prepared. The resulting materials were characterized by ICP-AES, N-2 physisorption, XRD, XPS, FT Raman, and UV-vis spectroscopies. The sol-gel derived materials were X-ray amorphous and possessed a high surface area after drying, and a marked mesoporosity in case of the aerogel. The morphology changed upon calcination in O-2 at 773 K, resulting in diminished surface area and a loss of micropores. The bismuth molybdenum oxide phases of the materials containing more than 50 wt% titania remained X-ray amorphous after calcination. The Bi- and Mo-content, the type of Bi- and Mo-precursors and their prehydrolysis, as well as the drying method had a major influence an the structural properties, and the surface and bulk composition of the aerogel and xerogels. Application of Bi-chloride and Mo-chloride precursors can result in significant deviation from the desired bulk composition, likely due to incomplete hydrolysis and evaporation during the subsequent drying and calcination steps.