In an effort to reduce the dependency on crude oil based fuels and to decrease pollutant emissions, hydrogen-CNG (HCNG) attracted a considerable attention with its low HC/CO2 emission and fast burn rate. In this study, a constant volume chamber with a single spark plug and a dual spark plug configuration was designed to obtain fundamental combustion characteristics of HCNG and to evaluate possible advantages of the dual spark plug over the single spark plug ignition setup. Various mixtures of hydrogen and CNG were systematically experimented to evaluate effects of hydrogen fraction to lean burn limit, combustion pressure, rate of heat release and emission characteristics for both configurations. With the current experimental results, it was clearly demonstrated that an appropriate mixture of HCNG along with a suitable spark plug configuration, could become a promising candidate to replace the crude oil based IC engine fuels to alleviate the dependency on the depleting petroleum resource and to meet the stricter emission regulation. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.