The performance of NiMo (12 wt% MoO3, 3 wt% NiO) supported on the mesoporous crystalline MCM-41 aluminosilicate for mild hydrotreating of a vacuum gasoil has been compared with that of an amorphous silica-alumina and a USY zeolite with the same Ni and Mo loadings. The MCM-41-based catalyst was seen to give superior HDS, HDN, and HC activities to the latter two catalysts in a one-stage operation using an untreated gasoil. The better performance of the former catalyst is explained by its higher surface area, the presence of uniform pores in the mesopore range, mild acidity, and stability. In the case of a two-stage operation using a pretreated feed, the MCM-41 catalyst showed a lower HC activity than USY, but higher than the amorphous silica-alumina while preserving its better selectivity to middle distillates.