This paper describes the functioning and current status of the European Commission's Major Accident Reporting System (MARS), dedicated to collect in a consistent way data on major industrial accidents involving dangerous substances from the Member States of the European Union under the requirements of the 'Seveso Directives', to analyse and statistically process them, and to distribute all non-confidential accidents data and analysis results to the Member States. This modern information exchange and analysis tool is made up of two connected parts: one for each local unit (i.e, for the Competent Authority of each Member State), and one central part for the European Commission. The local as well as the central parts of this network can serve both as data logging systems and, on different levels of complexity, as data analysis tools. The central database allows complex pattern analysis, identifying and analysing the succession of disruptive factors leading to an accident. On this basis, "lessons learned" can be formulated for the industry or regulatory bodies for further accident prevention. Results of various overall analyses of the contents of MARS are given. The availability of MARS data and analysis results is described.