The invention relates to a self-supported mixed metal sulfide (MMS) catalyst for hydrotreating hydrocarbon feedstock and to a method for preparing the catalyst. The self-supported MMS catalyst contains Ni:W in a mole ratio of 1:3 to 4:1, on a transition metal basis. The self supported MMS catalyst is characterized as having an HYD reaction rate constant of at least 15% higher than that of a catalyst comprising nickel sulfide alone or a catalyst comprising tungsten sulfide alone, when compared on same metal molar basis in hydrotreating of benzene as a feedstock at identical process conditions.