The main objective pursued in this work is to investigate the potential of hydrogen production from hazelnut shells by applying downdraft gasification technique. An experimental study was carried out using a pilot scale-5 kW-throated downdraft gasifier. During the experiments, the temperatures at zones of downdraft gasifier and pressure drops across the downdraft gasifier were recorded with an Analog to Digital (ATD) converter linked to computer at every 15 s. The flow rates of produced dry gas, combustible gas, hydrogen gas and the percentage of hydrogen gas in the produced gas were determined and illustrated. The effects of air fuel ratio and oxidation zone temperatures on the production of hydrogen gas were discussed. Additionally, the production of hydrogen gas from hazelnut shells was also estimated for a year. It was concluded that hazelnut shells could be easily converted to hydrogen gas by applying downdraft gasification technique. (C) 2000 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.