This invention describes a process for hydrogenation of an aromatic feedstock that as a catalytic composition uses a suspension of metal nanoparticles of a mean size of between 1 and 20 nanometers in at least one non-aqueous ionic liquid, whereby said suspension also contains at least one nitrogen-containing ligand, in which said metal nanoparticles comprise a transition metal in the zero-valence state, whereby the transition metal is selected from the groups 8, 9, 10 and 11 of the periodic table and in which said nitrogen-containing ligand comprises 1 to n nitrogen atoms, whereby n is an integer of between 1 and 20.