The vapour phase hydrogenation of naphthalene was investigated on a novel Ni-containing Si/Al mesoporous catalyst, comparing its chemical-physical characteristics and catalytic behaviour with those of a commercial Ni-SiO2/Al2O3 catalyst. The catalytic tests were carried out in a fixed bed reactor, operating at 6.0 MPa and the effect of various reaction parameters was investigated (temperature, contact time, H-2/naphthalene ratio, presence of dibenzothiophene (DBT) in the feed). The activity expressed as hourly productivity per litre of catalyst (as well as the yield %) was very similar to that of the commercial catalyst, while considerably better hourly productivity per kilogram of catalyst was observed both in hydrogenation and hydrogenolysis reactions, although the stability to DBT remained low. The higher activity for the mesoporous catalyst was even more interesting considering its lower Ni-content. However this catalyst was not stable at high temperature, due to deposition of heavy products and sintering of nickel particles, suggesting that its application should be limited to temperatures lower than 300 degreesC.