The surfactant-assisted Ni-Al2O3 catalysts are prepared by the homogeneous precipitation method with a surfactant/Al molar ratio ranging from 0.0 to 2.0. It has been investigated the effects of the surfactant on the physicochemical properties and the catalytic activities of the Ni-Al2O3 catalysts. The BET surface area of the catalysts decreases with increasing the surfactant content. The pore volume and pore size of the catalysts increase with increasing the surfactant content. XRD results indicate that all of the catalysts exhibit strong diffraction peaks corresponding to NiO and weak peaks corresponding to NiAl2O4. In the TPR results, the reduction peaks which indicates that the Ni particles strongly interacted with the support are present at between 668 and 688 degrees C. The activities of the prepared catalysts for methane steam reforming increase with increasing surfactant content in fresh and poisoned state due to an increase of pore volume and pore size. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.