Highly thermally stable lanthanum-doped ordered mesoporous alumina has been prepared in a sol–gel system with salicylic acid and citric acid as interfacial protectors. When the molar ratio of alumina to lanthanum is 25.5, most La 3+ ions in the resulting alumina structure showed tetracoordination. Moreover, the as-obtained sample exhibits a surface area of 305m 2 g −1 when calcined at 400°C and can maintain an ordered mesostructure with a high surface area of 205m 2 g −1 even when treated at 1000°C, demonstrating its high thermal stability.