The use of alternative energy is increasing with the concerns about global warming and the dwindling reserves of fossil fuels. Biodiesel and hydrogen are promising alternative fuels, and engine research has investigated the use of biodiesel/hydrogen mixtures. However, no study has examined the chemical kinetics of biodiesel and hydrogen mixtures. This study investigated the effects of hydrogen on the ignition delay of a methyl butanoate/n-heptane mixture. An experiment was conducted using a rapid compression machine (RCM) at 15 bar while varying the temperature (716-858 K) and hydrogen fraction in the fuel mixture (0, 25, 50, and 75%), and a numerical analysis was performed using CHEMKIN-PRO software to understand how the combustion process changes. The experimental and numerical analyses showed that, with hydrogen addition, the ignition delay increased. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.