Immobilization of small and homogeneously dispersed ruthenium nanoparticles stabilized by 4-(3-phenylpropyl)pyridine ligand (RuL) on functionalized multi-walled carbon nanotubes (RuL-MWCNT) have been prepared and characterized by elemental analysis and transmission electronic microscopy. A comparative hydrogenation study of unsaturated substrates using non-supported (RuL) and supported catalytic systems (RuL–MWCNT) was carried out. For all the substrates, the activity of the supported catalyst was higher towards the full hydrogenated product than that obtained using the non-supported one. Moreover, the catalytic effect of the support nature was studied using RuL immobilized on silica (RuL–SiO2), alumina (RuL–Al2O3) and activated carbon (RuL–AC). The best activities and selectivities were found for RuL–MWCNT system, maintaining its catalytic behaviour upon recycling.