During the last five years it is possible to observe an extreme effort concerning the aims of sustainable development and use of means of environmental policy for the purpose of integration of environmental issues into the decision making process. After more than twenty years experience with implementation of environmental impact assessment on the project level the conclusion has been reached worldwide that it is necessary to take into consideration the whole planning process. The process of impact assessment on environment has to be started much earlier than in the project stage. This article is devoted on the basis of the analysis of foreign experiences for the application of strategic environmental assessment in spatial planning in Slovakia.