Within the framework of the Regional Environmental Reconstruction Programme for South Eastern Europe (REReP), the Development of National Environmental Information Systems project (April 2001 to December 2003) set out to help the region’s countries and territories build their own environmental information systems. The purpose of this publication was to provide a snapshot of the existing environmental information systems in SEE, to reveal obstacles and challenges to system development, and to map future priorities as defined by the countries themselves. It was hoped that the document would be a useful tool for those working with environmental information systems in each country and for donors supporting their development.