Sustainable development has become one of the most discussed issues on national, regional and international levels. Together with policy development, the need to assess the current situation and the achieved progress in sustainability has arisen. In Lithuania integrated evaluations of sustainability are rather rare, therefore this paper aims to apply composite index for Lithuanian regions – counties. Research focuses on four regions of Lithuania: ones with the highest and with the lowest GDP values over the period of 2000–2010. The analysed indicators were normalized calculating T values and recalculating some of indicators to have them in the same direction and applying equal weight basis approach. The results reveal rather different development of selected regions. In all areas analysed (economy, environment, health and social issues) Vilnius County has improved most. Meanwhile situation in Tauragė region has only worsened. Though not only economic issues are important then assessing the development course, regions with higher economic development favour in general and their development is more stable and sustainable.