In this article nickel catalysts supported on mesoporous nanocrystalline gamma alumina with high surface area were prepared and employed in steam reforming of glycerol. The catalysts were characterized by X-ray diffraction (XRD), N-2 adsorption (BET), temperature programmed reduction and oxidation (TPR-TPO) and scanning electron microscopy techniques. The results showed that increasing in nickel loading decreased the BET area and pore volume and increased the nickel crystallite size. In addition, the increase in nickel loading improved the glycerol conversion and the 15 wt.% Ni/Al2O3 catalyst with surface area of 158.3 m(2) g(-1) and nickel crystallite size of 17.2 nm exhibited the highest activity in this reaction. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.