Molybdenum tetraalkylammonium thiosalts were used as precursors for the in situ formation of MoS2 catalysts for dibenzothiophene hydrodesulfurization. The influence of the chemical composition of precursors (R4N)(2)MoS4 With R=H+, CH3+ or C4H9+ and mechanical pressing of precursors on the composition and activity of prepared catalysts was investigated. The change of cation from proton to methyl- and to butylammonium increased the surface area and HDS activity of MoS2 catalysts. Extremely high surface area surpassing 200 m(2)/g was obtained for catalysts formed from tetrabutylammonium thiomolybdate. Significant difference was observed for pattern of thermal decomposition of alkylammonium thiosalts compared to ammonium ones. Unusual sponge-like morphology by reason of appearance of secondary porosity was observed in the case of tetrabutylammonium precursors.