In this work we investigate the effects of hydrogen addition on the flame structure of MILD combustion both experimentally and numerically using a laminar-jet-in-hot-coflow (LJHC) geometry. The addition of hydrogen appreciably decreases the flame height (similar to 25%), however only modestly affects the maximal flame temperature and the thickness of combustion zone. The NO distribution is dominated by mixing of the NO formed in the coflow with the reaction products of the diluted fuel, with negligible NO formation from the fuel in all flames studied. The numerical data are in reasonably good agreement with the measurements. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.