It is well known that the catalytic activity that presents a particular sulfide depend upon the transition metal that it possesses and of its location in the periodic table. In order to gain insight into the origin of these trends in activity, on terms of extended Mickel method, were carried out calculations for trimetallic unsupported M-Mo-W-S (M=Ni, Co, Fe or Cu) sulfide catalysts. The results of these calculations were used to identify electronic properties, such as band structure, density of states and average net charge, which showed that exists a direct correlation with the catalytic activity of the transition metal sulfides. In addition, was observed that the promotion of (Mo-W)S-2 precursors with M to form trimetallic M-Mo-W-S catalysts after sulfidation, increases the availability of electrons over the Fermi level, increasing the metallic character of the catalysts. (C) 2013 Elsevier B.V. All rights reserved.