The article discusses the challenges of harmonizing the national Environmental Assessment system with the requirements stipulated in the EU Association Agreement and tries to identify in this respect the necessary directions for development. The analysis of post-accession experience of some countries suggests that the critical factors in the process of reforming are the contextual ones that should be identified and assessed before harmonizing the national system with the EU framework. The authors argue that developing appropriate mechanisms for reforming the Environmental Assessment system that relies on a well-defined theoretical foundation would increase the chances that this would result in a functioning and effective system in practical terms.