The European list of aquatic macro-invertebrate taxa, and its associated ecological database, originated within the context of the AQEM project and have been extended during the STAR project. The AQEM/ STAR taxalist is a product of co-operation between applied freshwater ecologists and scientists from different zoological fields, applied partners and the administration. The basic idea is that a sound understanding of benthic invertebrate ecology is a prerequisite for the implementation of a biological approach to aquatic ecosystem management in Europe. The database has been generated under the management of BOKU (University of Natural Resources and Applied Life Sciences, Vienna) and UDE (University of Duisburg-Essen) and provides an important means of standardisation and unification of ecological classifications in Europe. This paper outlines the aims for setting up the AQEM/STAR macro-invertebrate taxalist and autecological database and provides a current summary of the numbers of aquatic orders, families, species, and species occurrences in 14 European countries. The number of available and applicable assignments of taxa to each ecological parameter is summarised and examples are given for different parameters and taxonomic groups. Gaps in the autecological information are identified and discussed. Besides its ecological relevance, the operational character of this database is underlined by the fact that it provides the associated taxon codes for each of five different European assessment systems for nearly 10,000 European macro-invertebrate taxa.