The oxo-diperoxo molybdenum(VI) complex MoO(O(2))(2).2QOH (QOH = 8-quinilinol) was prepared and characterized by elemental analysis, IR and UV-Vis spectra. The ionic liquids (ILs) [bmim][BF(4)], [hydemim][BF(4)], and [bmim][PF(6)] were characterized by (1)H-NMR and UV-Vis spectra. The epoxidation of a technical mixture of methyl oleate and methyl linoleate with H(2)O(2), in [bmim][BF(4)], [hydemim][BF(4)] and [bmim][PF(6)], catalyzed by MoO(O(2))(2).2QOH (QOH = 8-quinilinol) and with NaHCO(3) as co-catalyst has been studied for the first time. It was found that high conversions of methyl oleate and methyl linoleate to their respective oxidation products, as well as the total selectivity of their oxidation products to oxirane in [hydemim][BF(4)] were obtained. Also, the IL phases containing the Mo(VI) catalyst can be readily recycled by washing with diethyl ether and drying, and the Mo(VI) catalyst can be reused at least five times.