<p>Research on policy evaluation has gained in importance since the European Union introduced its new procedures on impact assessments in 2003. In the course of the EPOS project, the Institute for Ecological Economy Research (IOEW) and Ecologic Institute were organising the conference "Sustainable Development in Policy Assessment – Methods, Challenges and Policy Impacts", which took place from 15 until 16 June 2009 in Brussels. The conference seeked to contribute to the understanding of sustainability evaluation. Therefore, contributions were invited that tackle methodological challenges to sustainability evaluation, as well as the question of how the institutionalisation of sustainability evaluation can be improved.</p>&#13;