Hydrocracking has become a major oil refining process since its introduction in 1961. Developing improved catalysts for industrial processes involves the proper balance between activity, selectivity, and catalyst life; Hydrocracking catalysts consisting of combinations of nickel and tungsten oxides supported on a low (13 %) alumina, silica-alumina matrix containing 35 % Ultrastable Y zeolite were tested ina once-through mode. Catalyst performance was determined using a blend of light virgin and catalytic cycle oils for hydrocracking and a heavy catalytic cycle oil for denitrogenation. The best catalysts were estimated to be more than twice as active for hydrocracking as the reference catalyst;high selectivity to heavy naphtha,and near total denitrogenation and desulfurization were also achieved.