We investigated the removal of dibenzothiophene (DBT) and related compounds, 4-methyldibenzothiophene (4-MeDBT), 4,6-dimethyldibenzothiophene (4,6-DMeDBT), 2,8-dimethyldibenzothiophene (2,8-DMeDBT), and 1-benzothiophene (1-BT) from several oil media at room temperature under pressurized O-2 (0.6 MPa) by means of a three-phase reaction system consisting of the oil phase, an aqueous phase containing the phosphorus-free polyoxotungstate catalyst Na4W10O32 center dot 8H(2)O, H2O2, and tetraoctylammonium bromide, and the gas phase. Under conditions in which the initial DBT concentration in octane was 10.1 mM, the desulfurization ratio reached 87% after reaction for 6.5 h. The sulfur atoms in the initial DBT were well accounted for by the sulfur atoms in the residual DBT, the dibenzothiophene sulfone and dibenzothiophene 5-oxide in the octane phase, and the dibenzothiophene sulfone that precipitated. Prolonged reaction time to 18 h resulted in 92% desulfurization. The desulfurization of octane decreased in the order 2,8-DMeDBT DBT > 4-MeDBT > 1-BT 4,6-DMeDBT. Light oil and kerosene could also be desulfurized efficiently: after reaction for 6.5 h, the desulfurization ratios reached 77 and 78% for light oil and kerosene, respectively.