An efficient and green procedure has been developed for the synthesis of 1,8-dioxo-octahydroxanthenes derivatives. The reaction was carried out in water under ultrasound irradiation, using nanosized MCM-41-SO(3)H. In this method, several types of aromatic aldehyde, containing electron-withdrawing groups as well as electron-donating groups, were rapidly converted to the corresponding 1,8-dioxo-octahydroxanthenes in good to excellent yields. This novel synthetic method is especially favored because it provides a synergy of the nanosized MCM-41-SO(3)H and ultrasound irradiation which offers the advantages of high yields, short reaction times, simplicity and easy workup compared to the conventional methods reported in the literature.