Abstract The European Safety Reliability and Data Association (ESReDA) established in year 2000, a Working Group on Accident Investigation (WGAI) that ended in the year 2008. With the objective of improving the quality of accident investigation and as a consequence the learning from experience process and the safety performance, the working group tasked itself at two levels: the first one, at a societal, institutional and legal level, on the public accident investigation issue; the second one, at a methodological and organisational level, on the conduct of accident investigation. The underlying process that the working group followed was firstly to establish a state of the art of accident investigation practices and secondly to foster exchanges and dissemination of best practices through issuing guidelines, reports and by organising scientific seminars. This article summarises the working group achievements made visible in editing three reports and organising two ESReDA seminars in the area of safety investigation of accidents. The article presents a synthesis of the approach and main results, the lessons learned, some dilemmas and conflicts, several future challenges, recommendations and suggestions for action to the main stakeholders involving European and member state authorities, industrials, research centres and universities, and professionals of the rising accident investigation community.