Unsupported MoS 2 samples with surface areas ranging from 1 to 83 m 2 g −1 were prepared by treatment of different precursors in a H 2H 2S atmosphere at 673 K. Their catalytic properties were determined for several hydrotreating reactions. Dibenzothiophene hydrodesulfurization, and biphenyl and cyclohexene hydrogenations were found to be “texture-insensitive”, while pyridine hydrogenation and piperidine hydrodenitro-genation appeared to be “texture-sensitive”. It is proposed that the catalytic sites responsible for the reactions involving nitrogen-containing molecules are different from those where other reactions take place. These sites probably contain more atoms and are more dependent on the environment. The peculiar nature of the sites of nitrogen-containing molecule reactions is supported by comparison of the catalytic properties of these MoS 2 samples with those of a cobalt-promoted molybdenum sulfide catalyst.