The catalytic activity of niobium oxide-based materials, containing the same amount of Nb2O5 (similar to 15 wt%) and prepared by different methods, with that of pure Nb2O5 in the epoxidation of methyl oleate with hydrogen peroxide was compared. The catalytic performances of the catalyst prepared by impregnation do not differ substantially from the ones of Nb2O5. The performances of Nb-supported catalysts prepared by sol-gel can be modulated by controlling the process parameters. The high dispersion of the active NbOx species obtained by this preparation method gives very higher selectivity than in the case of pure Nb2O5. Morphologic and structural characterization of the catalysts helped justifying the obtained catalytic results in terms of activity and selectivity. (C) 2014 Elsevier B.V. All rights reserved.