TiO2-doped mesoporous silica (TDMS) was synthesized in situ from coal fly ash for photocatalytic degradation of organic dyes. The prepared TDMS is mainly composed of SiO2 and anatase TiO2 and has a sponge-like mesoporous structure with a high specific surface area of 297 m(2)/g. In photocatalytic experiments, TDMS shows good performance in the removal of dyes. The decoloration rates of both rhodamine B and acid orange II reached 99.9% within 6 h at a TDMS dosage of 4 g/L, and the total organic carbon (TOC) removal efficiency reached 90.3 and 84.1%, respectively. Furthermore, whereas the dye decoloration rate of TDMS is comparable to that of commercial TiO2 (anatase), it shows much better TOC removal efficiency. The results indicate that TDMS can be a potential and low-cost photocatalyst for treating water polluted with dyes.