Hydrogen was produced via steam reforming and oxidative steam reforming of a pyrolysis oil aqueous fraction, which was obtained via fractional condensation. The steam reforming experiments were carried out using a commercial nickel catalyst with and without a zirconia monolith as a pre-conversion catalyst. Addition of oxygen, which was examined at four different oxygen-to-carbon ratios, resulted in linearly decreasing H-2 yields using both catalyst combinations. The combined effect of the zirconia pre-conversion catalyst and the oxygen addition did, however, slow down the rate at which the H-2 yield decreased during the 4 h experiments. A long term experiment at the previously determined optimal conditions showed that the H-2 yield decreased clearly more rapidly than carbon conversion. The decrease in the H-2 yield was accompanied by a decrease in the selectivity towards CO2, and consequent increases in the selectivities of CO, CH4 and C-2 hydrocarbons. These changes indicated that the catalyst was continuously losing its activity towards the reforming of hydrocarbons and conversion of CO via the water-gas shift reaction. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.