In the present work, we report results of a comparison study of bimetallic NiMo and NiW hydrodesulfurization (HDS) catalysts supported on SBA-15 silica and trimetallic ones, prepared by co-impregnation (NiMoW) and mechanical mixing (NiMoANiW). The aim of this study was to inquire on the possibility of preparation of highly active supported trimetallic catalysts for deep HDS and to evaluate their efficiency in hydrodesulfurization of refractory sulfur-containing compounds. SBA-15 support and prepared bi- and trimetallic catalysts were characterized by nitrogen physisorption, small-angle and powder XRD, temperature programmed reduction, UV-vis DRS, Raman and HRTEM, and tested in the simultaneous HDS of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). It was found that the trimetallic NiMoW/SBA-15 catalyst prepared by co-impregnation showed the highest catalytic activity in HDS of both model compounds tested. As it was shown by TPR, DRS, Raman and HRTEM, this behavior can be attributed to the difference in the characteristics of Mo and W species in this trimetallic catalyst and in the corresponding bimetallic NiMo/SBA-15 and NiW/SBA-15 counterparts. (C) 2012 Elsevier Ltd. All rights reserved.