Hydrogen is an emerging alternative fuel, yet its properties like wide flammability range, extremely fast burning rate (order of magnitude larger compared to natural gas) and the considerably high amount of energy released when it burns or explodes render it as dangerous, if not handled with care. Hydrogen Incident Reporting Database (HIRD) is one of the various databases which have been generated to collect incident information in hydrogen industry. In this study, 32 chosen (from HIRD) hydrogen processing incidents have been analyzed to learn about their root causes. As a result of the study, statistical values about the effects, causes and consequences as well as a check-list for avoiding these incidents, have been developed. The support to risk assessment is mainly directed to the analysis of weak points and system optimization. For support of various aspects of risk analysis an extension of incident analysis and its documentation is recommended. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.