Due to the introduction of species and the huge modifications of river ecosystems by man, animal and plant communities in European rivers have changed fundamentally on a long term perspective. In the last few decades, serious problems have arisen from the degradation of riverine landscapes (e.g. drinking water supply, flood protection, loss of species diversity). Hence, there is now great need for ecological restoration of rivers. A common agreement in Europe is to base the assessment of river ecological status on the identification of reference conditions (water framework directive). The latter are e.g. for fish defined as conditions, where species composition, abundance and age structure of populations correspond totally or nearly totally to undisturbed conditions. Besides modelling and expert judgment, the use of historical data is considered as a possibility to define reference conditions.The aim of this presentation is to evaluate the possibilities of describing the distribution of fish species of the french and austrian alpine rivers before the major direct, systematic impacts (civil engineering works) were built. In countries, historical maps and written documents from the 19th and beginning of the 20th century were compiled and implemented in GIS. Based on particular examples, the authors will examine how main characteristics of fish assemblages can be evaluated along the river networks by using historical data: regional species distribution and local species richness, upstream limits of species migration, and definition of species habitat requirements by integrating (historical) abiotic data. Nevertheless, important features such as species abundance and age structure cannot be assessed. The value of historical data for current ecological questions will be also evaluated in relation to different types of data sources. Finally, the link between historical situations and the concept of reference conditions will be discussed.