Unsupported nickel-molybdenum sulfide hydrogenation catalysts are ex situ synthesized from precursor-aqueous-solution-in-decalin emulsions. A comparative analysis of the activity of the synthesized catalysts and the GO-38 commercial supported catalyst in polymeric petroleum resin hydrogenation is conducted. It is shown that the activity of the synthesized catalysts is higher than the activity of the supported catalyst at an identical concentration of the active metal in the reaction medium. The effect of the type and concentration of the emulsifier on the size of the emulsion droplets and the catalytic activity of the resulting catalyst is studied. It is shown that polymeric petroleum resins can be used instead of synthetic surfactants as an emulsifier in catalyst synthesis. An optimum Mo/Ni ratio (1/0.25) that provides the maximum degree of hydrogenation (100 and 78% for olefinic and aromatic moieties, respectively) is found. Catalyst activity varies only slightly after reuse in two or three runs; further, activity in the hydrogenation of aromatic moieties decreases, while activity in the hydrogenation of double bonds remains unchanged; in this case, the degree of dispersion does not change.