The aim of this article is to present an analysis of formal educational documents in the context of the sustainable development notion. This goal was realised by an analysis of the National Curriculum Framework documents from 2002 in comparison with the newest document from 2008. In addition, seven teaching programmes were analysed. On the grounds of the sustainable development definition and in the context of UNECE Strategy of Education for Sustainable Development, a list of direct and indirect linguistic indicators was created. To count the key words, the text editor Adobe Reader 9.0 was used. In the oldest version of the National Curriculum Framework, the key words defining sustainable development or their components occurred 119 times, in the newest - 165 times. The new version covers the scope of sustainable development in a wider range.