The accuracy of a new methodology to include differential diffusion in numerical simulations of reactive flows is illustrated for a set of laminar, axi-symmetric H-2/N-2-air diffusion flames. From the comparison of the calculations with the experimental data it is observed that when differential diffusion effects are properly taken into account in the transport equations in physical space, simulation results agree well with the experimental data. Ignoring differential diffusion effects is not acceptable, due to lack of H-2 diffusion close to the jet inlet. Overall, differential diffusion has a strong influence on the stabilization of the flame as well as on the chemical species concentrations. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.