Nanosize mesoporous tin oxide was prepared by a sonochemical approach, using tin ethoxide as the inorganic precursor and cetyltrimethylammonium bromide as the organic structure-directing agent. The formation of mesoporous SnO2 was confirmed by comparing its wide-angle X-ray diffractograms and IR spectra with previously reported data. The pore sizes measured from transmission electron microscope photographs were on the order of 3-5 nm. The Brunauer-Emmett-Teller surface area is reported after calcination at various temperatures and solvent extraction. The N-2 adsorption-desorption plot followed the H2 type hysteresis showing less defined pore size and pore distribution. The thermogravimetric analysis data show that most of the weight loss occurs in the temperature range of 40-400 degreesC in the as-prepared sample, indicating the removal of the surfactant. Approximately 32% of the sample weight is lost up to 400 degreesC, and the remaining tin oxide is stable. The porous tin oxide prepared in this way was used in dye-sensitized solar cells.