An experimental and numerical study on the combined effect of N-2/CO2 dilution and hydrogen addition on the laminar burning velocity (LBV) of methane-oxygen mixtures was conducted. The experiments were performed at atmospheric conditions using the heat flux method for effective equivalence ratios (phi(F)) varying from 0.7 to 1.3. The results show that the hydrogen addition causes an increase in LBV for all the mixture conditions. The variation in LBV based on hydrogen addition parameter (R-H) for all N-2 dilution conditions were following a linearly increasing trend. The strong effect of hydrogen addition on LBV is observed at lean and rich mixtures compared to that at near stoichiometric mixture conditions. The experimental results show that the percentage variation in LBV with R-H at rich mixture is more substantial at 75% N-2 dilution compared to that at 65% N-2 dilution. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.