The Eastern Enlargement of the EU and the Environment – the Case of PolandPoland is one of the most important accession candidates for the eastern enlargement of the European Union. Accession to the EU is a fundamental economic and administrative challenge for central and eastern European countries. Environmental policy is one of the most difficult topics of the current negotiations. The harmonisation of environmental standards and the investment required for compliance with EU legislation stimulate market demand for environmental technologies. The study develops a scenario which outlines the institutional and financial challenges and clarifies the demand-side dynamics of the Polish environmental market over time.To start with the study analyses the enlargement process, its environmental dimension and EU support mechanisms for applying countries in general and Poland in particular.The economic implications are shown in a survey of cost estimates resulting from the adoption of EU environmental standards by the new members The insights are used to construct a quantitative medium- and long-term scenario of the harmonisation process and the resulting market opportunities. Until 2005 the market volume can be estimated at some 30 billions DM, of which 7 to 8 billion DM could be served by imports. In the long term exists a need for additional investment of more than 50 billions DM, of which more than 25 billions may prove relevant for imports.