The Hydrogen Incident and Accident Database (HIAD) is being developed as a repository of systematic data describing in detail hydrogen-related undesired events (incidents or accidents). It is an open web-based information system serving various purposes such as a data source for lessons learnt, risk communication and partly risk assessment. The paper describes the features of the three HIAD modules - the Data Entry Module (DEM), the Data Retrieval Module (DRM) and the Data Analysis Module (DAM) - and the potential impact the database may have on hydrogen safety. The importance of data quality assurance process is also addressed. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.